Integrated circuit chips with fine-line metal and over-passivation metal

ABSTRACT

An integrated circuit chip includes a silicon substrate, a first circuit in or over said silicon substrate, a second circuit device in or over said silicon substrate, a dielectric structure over said silicon substrate, a first interconnecting structure in said dielectric structure, a first pad connected to said first node of said voltage regulator through said first interconnecting structure, a second interconnecting structure in said dielectric structure, a second pad connected to said first node of said internal circuit through said second interconnecting structure, a passivation layer over said dielectric structure, wherein multiple opening in said passivation layer exposes said first and second pads, and a third interconnecting structure over said passivation layer and over said first and second pads.

This application claims foreign priority to TW application No.095136115, filed on Sep. 29, 2006, which is herein incorporated byreference in its entirety.

This application is related to MEGICA Docket No. MEGA07-011US-TW06015-EOI, MEGA 07-01 IUS-TW06015-E02, MEGA 07-01IUS-TW06015-E04, MEGA 07-01 IUS-TW06015-E05, MEGA 07-011US-TW06015-E06and MEGA 07-011US-TW06015-E07, assigned to a common assignee.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an on-chip circuit unit to send electricalstimulus to other circuit units that are located on the same integratedcircuit (IC) chip and a method for forming the same. More particularly,the invention relates to an on-chip voltage-regulating circuit or avoltage converter to send electrical power to other circuit unitslocated on the same chip by way of a coarse conductor deposited over thepassivation layer.

2. Brief Description of the Related Art

Today many electronic devices are required to run at high speed and/orlow power consumption conditions. Moreover, a modern electronic system,module, or circuit board contains many different types of chips, such asCentral Processing Units (CPUs), Digital Signal Processors (DSPs),analog chips, DRAMs, SRAMs, Flashs and etc. Each chip is fabricatedusing different types and/or different generations of IC manufacturingprocess technologies. For example, in a modern notebook personalcomputer, the CPU chip may be fabricated using an advanced 65 nmtechnology with power supply voltage at 1.2 V, the analog chipfabricated using a 0.25 μm IC process technology with power supplyvoltage at 3.3 V, and the DRAM chip using a 90 nm IC process technologyat 1.5 V, and the flash chip using a 0.18 μm technology with powersupply voltage at 2.5 V. With varieties of supply voltages in a singlesystem, the on-chip voltage converter and/or voltage regulator becomedesirable. The DRAM chip may require an on-chip voltage converter and/orvoltage regulator to convert 3.3 V to 1.5 V and the flash chip may alsorequire an on-chip voltage converter to convert 3.3 V to 2.5 V Moreover,the on-chip voltage converter or regulator should provide a constantvoltage for the semiconductor devices located at different locations onan IC chip through on-chip power/ground buses. In this regard, anon-chip voltage regulator or an on-chip voltage converter affiliatedwith low parasitic power/ground lines is desired. In addition to theminimized energy consumption, the rippling effect that may occur inaccordance with fluctuation of load capacitance and resistance is alsoabated.

U.S. Pat. No. 6,495,442 B1 by Lin and et al. describes post-passivationschemes on top of IC chips. The post-passivaton scheme over the ICpassivation layer is used as the global, power, ground, or signaldistribution networks. The power/ground voltage is supplied from anexternal (outside of the chip) power supply source.

U.S. Pat. No. 6,649,509 B1 by Lin and et al. describes an embossingprocess to form post-passivation interconnection scheme over the ICpassivation layer to be used as the global distribution network forpower, ground, clock and/or signal.

SUMMARY OF THE INVENTION

An object of this invention is to provide an on-chip circuit unit tosend electrical stimulus to several devices or circuit units that arelocated on the same IC chip.

An object of this invention is to provide an on-chip voltage-regulatingdevice (voltage regulator) to send electrical power to several devicesor circuit units that are located on the same IC chip.

An object of this invention is to provide an on-chip voltage converterto send electrical power to several devices or circuit units that arelocated on the same IC chip.

Another object of the invention is to deliver electrical stimulus toseveral devices or circuit units with little loss due to the parasiticeffects.

Another object of the invention is to deliver electrical power toseveral devices or circuit units with little loss due to the parasiticeffects.

A further object is to deliver electrical power to several devices orcircuit units through the passivation opening and by way of a coarseconductor deposited over the passivation layer.

A still further object is to provide an over-passivation metalinterconnection distributing signals, power, or ground outputs from atleast one internal circuit or internal device to at least anotherinternal circuit or internal device.

Another object of the invention is to provide an over-passivation metalinterconnection distributing signals, power, or ground outputs from atleast one internal circuit or internal device to at least anotherinternal circuit or internal device without connection to ESD, driver orreceiver circuitry.

Yet another object of the invention is to provide an over-passivationmetal interconnection distributing signals, power, or ground outputsfrom at least one internal circuit or internal device to at leastanother internal circuit or device without connection to external(outside of the chip) circuitry.

Another object is to propagate a signal generated in the internalcircuits or internal devices to the external circuitry throughover-passivation metals and fine-line metals.

A further object of the invention is to provide an over-passivationmetal interconnection distributing signals, power, or ground outputsfrom at least one internal circuit or internal device to at leastanother internal circuit or internal device wherein an over-passivationcontacting structure can be connected with an off-chip circuit, andconnected to external circuitry.

A still further object is to provide an over-passivation metalinterconnection distributing an external power supply to internalcircuits and a contacting structure to the external power supply.

In accordance with the objects of the invention, a chip structure isprovided comprising an over-passivation metal interconnectiondistributing output voltage and/or current from a voltage regulator tointernal circuits.

Also in accordance with the objects of the invention, another chipstructure is provided comprising an over-passivation metalinterconnection distributing signals, power or ground outputs from atleast one internal circuit to at least another internal circuit.

Also in accordance with the objects of the invention, another chipstructure is provided comprising an over-passivation metalinterconnection distributing signals, power or ground outputs from atleast one internal circuit to at least another internal circuit and anover-passivation metal contacting structure connecting an off-circuitchip to external circuitry.

Also in accordance with the objects of the invention, another chipstructure is provided comprising an over-passivation metalinterconnection distributing an external power supply to internalcircuits and a contacting structure to the external power supply.

To enable the objectives, technical contents, characteristics andaccomplishments of the present invention, the embodiments of the presentinvention are to be described in detail in copperation with the attacheddrawings below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic representation of a conventional voltageregulator or voltage converter connected to internal circuits through afine-line metallization.

FIG. 1B is a schematic representation of a voltage regulator or avoltage converter connected to internal circuits through anover-passivation power bus (metal line, trace, or plane) in a firstpreferred embodiment of the present invention.

FIGS. 1C and 1D are schematic representation of a voltage regulator or avoltage converter connected to internal circuits throughover-passivation power and ground buses (metal lines, traces, or planes)in a first preferred embodiment of the present invention.

FIG. 2A is a top view layout of a conventional voltage regulator orvoltage converter connected to internal circuits through a fine-linemetallization.

FIG. 2B is a top view layout of a voltage regulator or a voltageconverter connected to internal circuits through an over-passivationpower bus (metal line, trace or plane) in a first preferred embodimentof the present invention.

FIG. 2C is a top view layout of a voltage regulator or a voltageconverter connected to internal circuits through over-passivation powerand ground buses (metal lines, traces or planes) in a first preferredembodiment of the present invention.

FIG. 3A is a cross-sectional representation of a conventional voltageregulator or voltage converter connected to internal circuits through afine-line metallization.

FIG. 3B is a cross-sectional representation of a voltage regulator or avoltage converter connected to internal circuits through anover-passivation power bus (metal line, trace or bus) in a firstpreferred embodiment of the present invention.

FIG. 3C is a cross-sectional representation of a voltage regulator or avoltage converter connected to internal circuits throughover-passivation power and ground buses (metal lines, traces or planesin two patterned circuit metal layers) in a first preferred embodimentof the present invention.

FIG. 3D is a cross-sectional representation of a voltage regulator or avoltage converter connected to internal circuits through anover-passivation power bus (metal line, trace or bus) in a firstpreferred embodiment of the present invention. This figure is similar toFIG. 3B except that an additional polymer layer is provided between thebottom-most over-passivation metal layer and the passivation layer.

FIG. 4 is a schematic representation of an example of a CMOS voltageconverter circuit in a preferred embodiment of the present invention.

FIG. 5A is a schematic representation of multiple internal circuitsconnected through a fine-line metallization structure under apassivation layer.

FIG. 5B is a schematic representation of multiple internal circuitsconnected through a thick and wide metal layer over a passivation layerto transmit a signal according to a second embodiment of the invention.

FIG. 5C shows a circuit diagram of an inverter, which can be applied tothe internal circuit 21 shown in FIG. 5B.

FIG. 5D shows a circuit diagram of an internal driver, which can beapplied to the internal circuit 21 shown in FIG. 5B.

FIG. 5E shows a circuit diagram of a tri-state buffer, which can beapplied to the internal circuit 21 shown in FIG. 5B.

FIG. 5F shows a circuit diagram of a tri-state buffer, which can beapplied to the internal circuit 21 shown in FIG. 5B, connected to asense amplifier connected to a memory cell.

FIG. 5G shows a circuit diagram of a gate switch, which can be appliedto the internal circuit 21 shown in FIG. 5B, connected to a senseamplifier connected to a memory cell.

FIG. 5H shows a circuit diagram of a latch circuit, which can be appliedto the internal circuit 21 shown in FIG. 5B, connected to a senseamplifier connected to a memory cell.

FIG. 5I shows a circuit diagram of a gate switch and internal driver,which can be applied to the internal circuit 21 shown in FIG. 5B,connected to a sense amplifier connected to a memory cell.

FIG. 5J shows a circuit diagram of a latch circuit and internal driver,which can be applied to the internal circuit 21 shown in FIG. 5B,connected to a sense amplifier connected to a memory cell.

FIG. 5K is a schematic representation of multiple internal circuitsconnected through a thick and wide metal layer over a passivation layerto transmit a signal according to a second embodiment of the invention.

FIG. 5L shows a circuit diagram of an internal receiver, which can beapplied to the internal circuit 21 shown in FIG. 5K.

FIG. 5M shows a circuit diagram of a tri-state buffer, which can beapplied to the internal circuit 21 shown in FIG. 5K.

FIG. 5N shows a circuit diagram of a tri-state buffer, which can beapplied to the internal circuit 21 shown in FIG. 5K, connected to asense amplifier connected to a memory cell.

FIG. 5O shows a circuit diagram of a gate switch, which can be appliedto the internal circuit 21 shown in FIG. 5K, connected to a senseamplifier connected to a memory cell.

FIG. 5P shows a circuit diagram of a latch circuit, which can be appliedto the internal circuit 21 shown in FIG. 5K, connected to a senseamplifier connected to a memory cell.

FIG. 5Q shows a circuit diagram of a gate switch and internal receiver,which can be applied to the internal circuit 21 shown in FIG. 5K,connected to a sense amplifier connected to a memory cell.

FIG. 5R shows a circuit diagram of a latch circuit and internalreceiver, which can be applied to the internal circuit 21 shown in FIG.5K, connected to a sense amplifier connected to a memory cell.

FIG. 5S is a schematic representation of multiple internal circuitsconnected through a thick and wide metal layer over a passivation layerto transmit an analog signal according to a second embodiment of theinvention.

FIG. 5T shows a circuit diagram of a differential amplifier, which canbe applied to the internal circuit 21 shown in FIG. 5S.

FIGS. 5U-5Z show a schematic representation of a memory chip with anaddress bus and a data bus over a passivation layer.

FIG. 6A is a top view layout of a conventional distribution of signalsfrom an internal circuit to other internal circuits.

FIG. 6B is a top view layout of signal distribution, wherein an internalcircuit sends signals to other internal circuits through anover-passivation interconnection scheme, requiring no solder bump and nooff-chip circuits, in a second preferred embodiment of the presentinvention.

FIG. 7A is a cross-sectional representation of a conventionaldistribution of signals from an internal circuit to other internalcircuits.

FIG. 7B is a cross-sectional representation of signal distribution,wherein an internal circuit sends signals to other internal circuitsthrough an over-passivation interconnection scheme, requiring no solderbump and no off-chip circuits, in a second preferred embodiment of thepresent invention.

FIG. 7C is a cross-sectional representation of signal distribution,wherein an internal circuit sends signals to other internal circuitsthrough an over-passivation scheme, requiring no solder bump and nooff-chip circuits, in a second preferred embodiment of the presentinvention. Two over-passivation scheme comprises two metal layers.

FIG. 7D is a cross-sectional representation of signal distribution,wherein an internal circuit sends signals to other internal circuitsthrough an over-passivation interconnection scheme. This figure issimilar to FIG. 7B except that an additional polymer layer is providedbetween the passivation layer and the bottom-most over-passivation metallayer.

FIG. 8A is a schematic representation of a conventional distribution ofsignals from internal circuits to the external circuits through off-chipcircuits using fine-line scheme.

FIGS. 8B, 8D, 8E and 8F are schematic representations of a signalgenerated in the internal circuits propagated to an external circuitrythrough over-passivation metals and fine-line metals in a thirdpreferred embodiment of the present invention, and through off-chipcircuits.

FIG. 8C is a schematic representation of a signal transmitted from anexternal circuit to an internal circuit through over-passivation metalsand fine-line metals in a third preferred embodiment of the presentinvention, and through off-chip circuits.

FIG. 9A is a top view layout of a conventional distribution of signalsfrom internal circuits to the external circuits through off-chipcircuits using a fine-line scheme.

FIGS. 9B is a top view layout of multiple internal circuits connected toan off-chip circuit through a thick and wide metal trace, bus or planeover a passivation layer.

FIG. 9C is a top view layout of multiple internal circuits connected toan off-chip circuit through a thick and wide metal trace, bus or planeover a passivation layer, wherein the off-chip circuit includestwo-stage cascade off-chip driver 421.

FIG. 9D is a top view layout of multiple internal circuits connected toan off-chip circuit through a thick and wide metal trace, bus or planeover a passivation layer, wherein the off-chip circuit includesfour-stage cascade off-chip driver 42.

FIG. 10A is a cross-sectional representation of a conventionaldistribution of signals from internal circuits to the external circuitsthrough off-chip circuits using fine-line scheme.

FIGS. 10B-10E and 10G-10I are cross-sectional representations ofmultiple internal circuits connected to an off-chip circuit through athick and wide metal trace, bus or plane over a passivation layeraccording to a third preferred embodiment of the present invention.

FIG. 10F is a cross-sectional representation of multiple internalcircuits connected to an off-chip circuit through a metal trace, bus orplane under a passivation layer, with a wire wirebonded to a relocatedpad on a passivation layer, according to a third preferred embodiment ofthe present invention.

FIG. 11A is a schematic representation of an example of an off-chipdriver circuit, which can be applied to the I/O circuit 42 shown in FIG.8B, in the third preferred embodiment of the present invention.

FIG. 11B is a schematic representation of an example of an off-chipreceiver circuit, which can be applied to the I/O circuit 42 shown inFIG. 8C, in the third preferred embodiment of the present invention.

FIG. 11C is a schematic representation of an example of an off-chiptri-state buffer, which can be applied to the I/O circuit 42 shown inFIG. 8B, in the third preferred embodiment of the present invention.

FIG. 11D is a schematic representation of an example of an off-chipdriver circuit, which can be applied to the I/O circuit 42 shown in FIG.8E, in the third preferred embodiment of the present invention.

FIG. 11E is a schematic representation of an example of an off-chiptri-state buffer, which can be applied to the I/O circuit 42 shown inFIG. 8C, in the third preferred embodiment of the present invention.

FIG. 11F is a schematic representation of an example of an ESDconnection, which can be applied to the ESD circuit 43 shown in FIGS.8B, 8C, 8E and 8F, in the third preferred embodiment of the presentinvention.

FIG. 11G is a schematic representation of an example of a four-stagecascade off-chip driver circuit, which can be applied to the I/O circuit42 shown in FIG. 8F, in the third preferred embodiment of the presentinvention.

FIG. 11H is a schematic representation of an example of two ESDconnections, which can be applied to the ESD protection circuit 43 shownin FIG. 8D, in the third preferred embodiment of the present invention.

FIG. 12A is a schematic representation of a conventional distribution ofexternal power supply to internal circuits.

FIG. 12B is a schematic representation of distribution of external powersupply to internal circuits through over-passivation metals in a fourthpreferred embodiment of the present invention. An ESD protection circuitis connected to the over-passivation metals.

FIG. 12C is a schematic representation of distribution of external powersupply and external ground to internal circuits through over-passivationmetals in a fourth preferred embodiment of the present invention. Bothpower and ground nodes of internal circuits are connected to theover-passivation metals. An ESD protection circuit is connected to theover-passivation metals.

FIG. 12D is a schematic representation of distribution of external powersupply and external ground to internal circuits through over-passivationmetals in a fourth preferred embodiment of the present invention. Morethan one ESD protection circuits are connected to the over-passivationmetals.

FIG. 12E is a schematic representation of an example of an ESDprotection circuit, which can be applied to the ESD circuit 44 or 45shown in FIGS. 12B-12D, in the fourth preferred embodiment of thepresent invention.

FIG. 13A is a top view layout of a conventional distribution of externalpower supply to internal circuits.

FIG. 13B is a top view layout of distribution of external power supplyto internal circuits through over-passivation metals in a fourthpreferred embodiment of the present invention. An ESD protection circuitis connected to the over-passivation metals.

FIG. 13C is a top view layout of distribution of external power supplyand external ground to internal circuits through over-passivation metalsin a fourth preferred embodiment of the present invention. Both powerand ground nodes of internal circuits are connected to theover-passivation metals. An ESD protection circuit is connected to theover-passivation power and ground traces, buses or planes.

FIG. 14A is a cross-sectional representation of a conventionaldistribution of external power supply to internal circuits.

FIG. 14B is a cross-sectional representation of distribution of externalpower supply to internal circuits through over-passivation metals in afourth preferred embodiment of the present invention. An ESD protectioncircuit is connected to the over-passivation metals.

FIG. 14C is a cross-sectional representation of distribution of externalpower supply and external ground to internal circuits throughover-passivation metals in a fourth preferred embodiment of the presentinvention. Both power and ground nodes of internal circuits areconnected to the over-passivation metals. The power lines, traces orplanes are in the second over-passivation metal layer, while the groundlines, traces or planes are in the first over-passivation metal layerunder the second over-passivation metal layer. An ESD protection circuitis connected to the over-passivation metals.

FIG. 14D is a cross-sectional representation of distribution of externalpower supply to internal circuits through over-passivation metals in afourth preferred embodiment of the present invention. An ESD protectioncircuit is connected to the over-passivation metals. This figure issimilar to FIG. 14B except that an additional polymer layer is formedbetween the bottom-most over-passivation metal layer and the passivationlayer.

FIG. 15A and FIG. 15B are starting materials for all embodiments ofpresent invention. The starting materials are conventional IC chips ofsilicon wafers (before dicing apart) fabricated by the conventional ICprocess technologies. An over-passivation scheme of present invention isto be built over the conventional IC chip. FIG. 15B differs from FIG.15A in having an optional metal cap over a metal pad exposed by anopening in the passivation layer.

FIG. 15C to FIG. 15L show process steps of forming an over-passivationscheme with two metal layers. Each metal layer is formed by theembossing process.

FIG. 16A to FIG. 16L show process steps of forming an over-passivationscheme with two metal layers. The first over-passivation metal layer isformed by a double-embossing process, while the second over-passivationmetal layer is formed by a single-embossing (an embossing) process.

FIG. 17A to FIG. 17J show process steps of forming an over-passivationscheme with three metal layers. The first and second over-passivationmetal layers are formed by a double-embossing process, while the third(top-most) over-passivation metal layer is formed by a single-embossing(an embossing) process.

FIG. 18A to FIG. 18I show process steps of forming an over-passivationscheme with three metal layers. The first and third over-passivationmetal layers are formed by a single-embossing (an embossing) process,while the second over-passivation metal layer is formed by adouble-embossing process.

FIG. 19A to FIG. 19I show process steps of forming an over-passivationscheme with two metal layers. The first over-passivation metal layer isformed by a double-embossing process, while the second (top-most)over-passivation metal layer is formed by a single-embossing (anembossing) process.

FIG. 20 illustrates models for calculating capacitance per unit lengthfor metal lines or traces in the over-passivation scheme and thefine-line scheme.

FIGS. 21 and 22 show top views of a MOS transistor that can be a PMOStransistor or an NMOS transistor.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment Over-PassivationPower/Ground Buses with a Voltage Regulator or a Voltage Converter

FIGS. 1B, 1C, 2B, 2C, 3B, 3C, and 3D illustrate the first preferredembodiment of the present invention. FIGS. 1B and 1C show a simplifiedcircuitry diagram where metal traces 81 and/or 82 over a passivationlayer 5 connect a voltage regulator or voltage converter 41 and internalcircuits 21, 22, 23 and 24 to distribute a power voltage or a groundreference voltage, wherein the passivation layer 5 is presented by adotted line, coarse traces mean the traces formed over the passivationlayer 5, and fine traces mean the traces formed under the passivationlayer 5. FIGS. 2B and 2C show top views of semiconductor chips realizingthe circuitry shown in FIGS. 1B and 1C, respectively, wherein coarsetraces mean the traces formed over the passivation layer 5, and finetraces mean the traces formed under the passivation layer 5. FIGS. 3Band 3C show cross-sectional views of semiconductor chips realizing thecircuitry shown in FIGS. 1B and 1C, respectively. FIGS. 2B and 2C showtop views of the semiconductor chips shown in FIGS. 3B and 3C,respectively.

In this invention, an on-chip voltage regulator or voltage converter 41sends electrical power to several internal devices 21, 22, 23 and 24 (orcircuits), wherein the voltage regulator or voltage converter and theinternal devices are formed in and on a silicon substrate 1 within asame IC chip. Through openings 511, 512 and 514 in a passivation layer5, and by way of a coarse metal conductor 81 deposited over thepassivation layer, electrical power output from the voltage regulator orvoltage converter 41 is delivered to several devices or circuit units21, 22, 23 and 24 with little loss or parasitic effects. The advantageof this design is that, affiliated with the regulated power source andwith the coarse metal conductor, the voltage to the next level at theload of internal circuits can be controlled at a voltage level with highprecision. When the reference number of 41 is a voltage regulator, theoutput voltage Vcc of the voltage regulator 41 is within +10% and −10%of the desired voltage level, and preferred within +5% and −5% of thedesired voltage level, insensitive to voltage surge or large fluctuationat the input node connected with an external power supply Vdd input fromthe power metal trace 81P. Alternatively, the voltage regulator 41 mayhave an output node at a voltage level of Vcc output from the voltageregulator 41 and an input node at a voltage level of Vdd supplied froman external circuit, wherein a ratio of a difference of the voltagelevel of Vdd minus the voltage level of Vcc to the voltage level of Vddis less than 10%.

Hence, circuit performance can be improved. The voltage regulator 41 mayhave an output of between 1 volt and 10 volts, and preferred between 1volt and 5 volts.

In some applications, if the chip requires a voltage level Vcc differentfrom the voltage level Vdd of the external power supply, a voltageconverter may be installed in the chip. The reference number of 41 mayindicate the voltage converter. The on-chip voltage converter 41, inaddition to the voltage regulating circuit, is desirable in this case toconvert the voltage level Vdd of the external power supply to thevoltage level Vcc required in the chip. The converter may output avoltage level Vcc higher than the voltage Vdd at the input node.Alternatively, the converter may output a voltage level Vcc lower thanthe voltage Vdd at the input node. The voltage converter may have anoutput of between 1 volt and 10 volts, and preferred between 1 volt and5 volts. When the voltage level of Vcc ranges from 0.6 volts to 3 volts,the voltage level of Vdd ranges from 3 volts to 5 volts. When thevoltage level of Vcc ranges from 0.6 volts to 2 volts, the voltage levelof Vdd ranges from 2 volts to 3 volts. For example, when the voltagelevel of Vcc is 2.5 volts, the voltage level of Vdd is 3.3 volts. Whenthe voltage level of Vcc is 1.8 volts, the voltage level of Vdd is 3.3volts. When the voltage level of Vcc is 1.8 volts, the voltage level ofVdd is 2.5 volts. When the voltage level of Vcc is 3.3 volts, thevoltage level of Vdd is 5 volts.

FIGS. 1A, 2A, and 3A show a circuitry diagram, a top view and across-sectional view, respectively, according to the prior art of how avoltage regulator and/or a voltage converter 41 is connected to internalcircuits 20, comprising 21, 22, 23 and 24. The voltage regulator and/ora voltage converter 41 receives an external power voltage Vdd, outputs apower voltage Vcc, and delivers the power Vcc to internal circuits 20,comprising 21, 22, 23 and 24, using IC fine-line metal traces 6191 and61 under a passivation layer 5, the IC fine-line metal traces 61comprising segments of 618, 6111, 6121 a, 6121 b, 6121 c and 6141. Thefine-lien metal traces 6191 and 61, located under the passivation layer5 and fabricated using the conventional IC process and materials.However, thick metal layers (for example, as thick as 5 μm) or thickdielectric layers (for example, as thick as 5 μm) are not easilyprovided using the conventional IC process and materials. Thereby, theIC fine-line metal lines or traces 6191 and 61 have high resistance andcapacitance per unit length, causing IR voltage drop, noises, signaldistortion, propagation time delay, and high power consumption and heatgeneration.

FIG. 1B shows the circuit schematics of the present invention. In thisinvention, the voltage regulator and/or the voltage converter 41receives a voltage Vdd from an external power supply, and outputs avoltage Vcc for the internal circuits 20, comprising 21, 22 23, and 24.The output voltage Vcc at node P is distributed to the power nodes Tp,Up, Vp and Wp of the internal circuits 21, 22, 23 and 24, respectively,first up through a passivation opening 519′ in the passivation layer 5,then through a thick metal trace 81 over the passivation layer 5, thendown through the passivation openings 511, 512, and 514 in thepassivation layer 5, and then through the fine-line metal traces 61′ tothe internal circuits 20: particularly through the segment 611 of thefine-line metal traces 61′ to the internal circuit 611; particularlythrough the segments 612 a and 612 b of the fine-line metal traces 61′to the internal circuit 22; particularly through the segments 612 a and612 c of the fine-line metal traces 61′ to the internal circuit 23; andthrough the segment 614 of the fine-line metal traces 61′ to theinternal circuit 24.

The internal circuits 20, comprising 21, 22, 23 and 24, each comprise atleast a PMOS transistor having a source connected to the fine-line metaltraces 61′, for example. Each of the internal circuits 20, comprising21, 22, 23 and 24, may include a NMOS transistor having a ratio of aphysical channel width thereof to a physical channel length ranging from0.1 and 20, ranging from 0.1 and 10 or preferably ranging from 0.2 and2. Alternatively, each of the internal circuits 20, comprising 21, 22,23 and 24, may include a PMOS transistor having a ratio of a physicalchannel width thereof to a physical channel length ranging from 0.2 and40, ranging from 0.2 and 40 or preferably ranging from 0.4 and 4.

The invented chip structure in FIG. 1B uses a coarse metal conductor 81as a carrier of the power/ground lines, traces, or planes. In this case,the voltage drop and noise is much reduced since the coarse metalconductor 81 has lower resistance and capacitance than the fine-linemetal traces 618 shown in FIG. 1A of the prior art.

The internal circuits, or internal circuit units 20, shown in all of theembodiments, comprise two NOR gates 22 and 24, one NAND gate 23, and oneinternal circuit 21, for example. The internal circuits 20, 21, 22, 23,and 24 can be any type of IC circuits, such as NOR gate, NAND gate, ANDgate, OR gate, operational amplifier, adder, multiplexer, diplexer,multiplier, A/D converter, D/A converter, CMOS transistor, bipolar CMOStransistor or bipolar circuit. Each of the internal circuit NOR gates 22and 24 and NAND gate 23 has three input nodes Ui, Wi or Vi one outputnode Uo, Wo or Vo, one Vcc node Up, Wp or Vp, and one Vss node Us, Ws orVs. The internal circuit 21 has one input node Xi, one output node Xo,one Vcc node Tp and one Vss node Ts. Each of the internal circuits orinternal circuit units 20, comprising 21, 22, 23, and 24, usually hassignal nodes, power nodes, and ground nodes.

FIGS. 2B and 3B provide the top view and cross-sectional view,respectively, of the circuitry diagram shown in FIG. 1B. It is notedthat, in FIG. 3B, the fine-line metal structures 611, 612, 614, 619 and619′ can be composed of stacked fine-line metal pads 60 and via plugs60′ filled in the vias 30′. The upper vias 30′ are substantially alignedwith the lower ones; the upper fine-line metal pads 60 are substantiallyaligned with the lower ones; the upper via plugs 60 are substantiallyaligned with the lower ones. Referring to FIGS. 1B, 2B and 3B, thefine-line metal traces or plane 612 comprises multiple portions 612 a,612 b and 612 c, and is used for the local power distribution.

The thick metal traces or plane 81 over the passivation layer 5 is usedfor global power distribution and connects the fine-line metal traces orplane 619′, 611, 612 and 614. The thick metal trace or plane 81 over thepassivation layer 5, shown in FIGS. 1B and 2B, may be composed of onlyone patterned circuit layer 811, as shown in FIG. 3B, or multiplepatterned circuit layers, not shown. The patterned circuit layer 811,such as a power plane, bus, trace or line, to distribute a power voltageVcc is realized from the concept of the coarse trace 81 shown in FIGS.1B and 2B. When the thick metal traces or plane 81 over the passivationlayer 5, shown in FIG. 2, is composed of multiple patterned circuitlayers, a polymer layer, such as polyimide (PI), benzocyclobutene (BCB),parylene, epoxy-based material, photoepoxy SU-8, elastomer or silicone,may be between the neighboring patterned circuit layers, separating thepatterned circuit layers. A polymer layer 99, such as polyimide (PI),benzocyclobutene (BCB), parylene, epoxy-based material, photoepoxy SU-8,elastomer or silicone, may be on the topmost one of the patternedcircuit layers, separated by the above mentioned polymer layers, overthe passivation layer, not shown, or on the only one patterned circuitlayer 811, as shown in FIGS. 3B and 3D. Alternatively, A polymer layer95, such as polyimide (PI), benzocyclobutene (BCB), parylene,epoxy-based material, photoepoxy SU-8, elastomer or silicone, may bebetween the passivation layer and the bottommost one of the patternedcircuit layers, separated by the above mentioned polymer layers, notshown, or between the passivation layer 5 and the only one patternedcircuit layer 811, as shown in FIG. 3D. The polymer layer 95 may have athickness between 2 and 30 micrometers. Multiple openings 9519, 9519′,9511, 9512 and 9514 in the polymer layer 95 are substantially alignedwith the openings 519, 519′, 511, 512 and 514 in the passivation layer5, respectively. The openings 9519, 9519′, 9511, 9512 and 9514 in thepolymer layer 95 expose the pads (including 6190 and 6190′) exposed bythe openings 519, 519′, 511, 512 and 514 in the passivation layer 5,respectively.

Some openings 9519 and 9519′ in the polymer layer 95 have lower portionshaving widths or transverse dimensions smaller than those of theopenings 519 and 519′ in the passivation layer 5 aligned with theopenings 9519 and 9519′, respectively. The polymer layer 95 covers aportion of the pads 6190 and 6190′ exposed by the openings 519 and 519′in the passivation layer 5. The shape of the openings 519 and 519′ froma top perspective view may be round, square, rectangular or polygon. Ifthe openings 519 and 519′ are round, the openings 519 and 519′ may havea diameter of between 0.1 and 200 microns, between 1 and 100 microns,or, preferably, between 0.5 and 30 microns. If the openings 519 and 519′are square, the openings 519 and 519′ may have a width of between 0.1and 200 microns, between 1 and 100 microns, or, preferably, between 0.1and 30 microns. If the openings 519 and 519′ are rectangular, theopenings 519 and 519′ may have a width of between 0.1 and 200 microns,between 1 and 100 microns, or, preferably, between 0.1 and 30 microns,and a length of between 1 micron and 1 centimeter. If the openings 519and 519′ are polygon having more than five sides, the openings 519 and519′ have a greatest diagonal length of between 0.1 and 200 microns,between 0.5 and 100 microns, or, preferably, between 0.1 and 30 microns.Alternatively, the openings 519 and 519′ have a greatest transversedimension of between 0.1 and 200 microns, between 1 and 100 microns, or,preferably, between 0.1 and 30 microns. In a case, the openings 519 and519′ have a width of between 30 and 100 microns, with the lower portionof the openings 9519 and 9519′ in the polymer layer 95 having a width ofbetween 20 and 100 microns.

Some openings 9511, 9512 and 9514 in the polymer layer 95 have lowerportions having widths or transverse dimensions greater than those ofthe openings 511, 512 and 514 in the passivation layer 5 aligned withthe openings 9511, 9512 and 9514, respectively. The openings 9511, 9512and 9514 in the polymer layer 95 further expose the passivation layer 5close to the openings 511, 512 and 514. The shape of the openings 511,512 and 514 from a top perspective view may be round, square,rectangular or polygon. If the openings 511, 512 and 514 are round, theopenings 511, 512 and 514 may have a diameter of between 0.1 and 200microns, between 1 and 100 microns, or, preferably, between 0.5 and 30microns. If the openings 511, 512 and 514 are square, the openings 511,512 and 514 may have a width of between 0.1 and 200 microns, between 1and 100 microns, or, preferably, between 0.1 and 30 microns. If theopenings 511, 512 and 514 are rectangular, the openings 511, 512 and 514may have a width of between 0.1 and 200 microns, between 1 and 100microns, or, preferably, between 0.1 and 30 microns, and a length ofbetween 1 micron and 1 centimeter. If the openings 511, 512 and 514 arepolygon having more than five sides, the openings 511, 512 and 514 havea greatest diagonal length of between 0.1 and 200 microns, between 1 and100 microns, or, preferably, between 0.1 and 30 microns. Alternatively,the openings 511, 512 and 514 have a greatest transverse dimension ofbetween 0.1 and 200 microns, between 1 and 100 microns, or, preferably,between 0.1 and 30 microns. In a case, the openings 511, 512 and 514have a width of between 5 and 30 microns, with the lower portion of theopenings 9511, 9512 and 9514 in the polymer layer 95 having a width ofbetween 20 and 100 microns.

The above-mentioned description concerning the openings 519, 519′, 511,512 and 514 in the passivation layer 5 and the openings 9519, 9519′,9511, 9512 and 9514 in the polymer layer 95 can be applied to theembodiments shown in 15A-15L, 16A-16L, 17A-17J, 18A-18I and 19A-19I.

One of the patterned circuit layers, such as 811 shown in FIGS. 3B and3D, composing the thick metal trace or plane 81 over the passivationlayer 5 may comprise an adhesion/barrier/seed layer 8111, and a bulkconduction metal layer 8112. The methods to form the patterned circuitlayer 811 and the specification thereof may follow the methods to formthe patterned circuit layer 801, 802 or 803 and the specificationthereof shown in FIGS. 15A-15L, 16A-16L, 17A-17J, 18A-18I and 19A-19I.

In FIGS. 1B, 2B and 3B, an external power supplies a voltage level Vddat a metal pad 8110 connected to a metal pad 6190 of a topmost one offine-line circuit metal layers 619 under the passivation layer 5 throughan opening 519 in the passivation layer 5, and inputs to the regulatoror the voltage converter 41. The regulator or the voltage converter 41outputs a power voltage to supply the internal circuits 21, 22, 23 and24 through the fine-line circuit metal layers 619′, thick patternedtrace or plane 811 and fine-line circuit metal layers 611, 612 and 614.The fine-line circuit layers 619, 619′, 611, 612 and 614 are separatedby thin-film insulating layers 30, such as silicon oxide.

Though FIG. 3B shows only one patterned circuit layer 81 fordistributing a regulated or converted power voltage of Vcc, multiplepatterned circuit layers with one or more polymer layers depositedtherebetween can be formed over the passivation layer 5 and used todistribute a regulated or converted power voltage of Vcc. Metal tracesor planes in different patterned circuit layers are connected throughthe openings in the polymer layer therebetween.

FIGS. 1A, 2A and 3A show the corresponding prior art. As figures revealthe external power supply at a voltage level Vdd inputs the regulator orthe voltage converter 41 through the pad 6190 exposed by the opening 519in the passivation layer 5 and through the fine-line circuit layers 619(comprising stacked fine-line metal pads and vias). The output power atvoltage level Vcc outputs from the regulator or the voltage converter 41is distributed to supply the voltage of Vcc to the internal circuits 21,22, 23 and 24 only through IC fine line interconnection 61 comprisingsegments 6191′, 618, 6111, 6121 and 6141. Significant energy loss andspeed reduction can be seen in the prior art.

In FIGS. 1B, 2B, 3B and 3D, the ground voltage is denoted as Vss withoutdetailing the circuit schematics, layout and structure for distributingthe ground voltage. FIGS. 1C, 2C and 3C describe the circuit schematics,top view and cross-sectional view, respectively, showing the thick metaltraces or planes 81 and 82 over the passivation layer 5 for distributingboth of the power supply voltage of Vcc and the ground reference voltageof Vss. The structure 82 of distributing the ground reference voltage ofVss is similar to the above mentioned structure 81 of distributing thepower supply voltage of Vcc, except that a common ground voltage Vss isprovided for the regulator or voltage converter 41 and the internalcircuits 21, 22, 23 and 24 through the thick metal trace or plane 82.That means the external ground node Es may be connected to the groundnode Rs of the regulator or voltage converter 41 and to the internalground node Ts, Us, Vs, Ws of the internal circuits 21, 22, 23 and 24.In FIGS. 1C, 2C and 3C, the point Es connected to a ground source of anexternal circuitry at a voltage level Vss is connected to (1) the groundnode Rs of the regulator or the converter 41 through an opening 529 inthe passivation layer 5, and (2) the ground nodes Ts, Us, Vs and Ws ofthe internal circuits 21, 22, 23 and 24 through the thick metal lines,buses or traces 82 over the passivation layer 5, the openings, 521, 522and 524 in the passivation layer 5, and fine-line metal structures 621,622 (comprising 622 a, 622 b and 622 c) and 624.

FIG. 3C shows two patterned circuit layers 812 and 821 over thepassivation layer 5, used for distributing a power voltage Vcc and aground reference voltage Vss, respectively. The bottom one 821 of thepatterned circuit layers 812 and 821, such as a ground plane, bus, traceor line, to distribute a ground reference voltage Vss is realized fromthe concept of the coarse trace 82 shown in FIGS. 1C and 2C. The top one812 of the patterned circuit layers 812 and 821, such as a power plane,bus, trace or line, to distribute a power voltage Vcc is realized fromthe concept of the coarse trace 81 shown in FIGS. 1C and 2C. A polymerlayer 98, such as polyimide, benzocyclobutene (BCB), parylene,epoxy-based material, photoepoxy SU-8, elastomer or silicone, having athickness of between 2 and 30 microns, separates the patterned circuitlayers 821 and 812. Another polymer layer 99, such as polyimide,benzocyclobutene (BCB), parylene, epoxy-based material, photoepoxy SU-8,elastomer or silicone, having a thickness of between 2 and 30 microns,covers the top patterned circuit layer 812. Alternatively, anotherpolymer layer, such as benzocyclobutene (BCB), polyimide, parylene,epoxy-based material, photoepoxy SU-8, elastomer or silicone, having athickness of between 2 and 30 microns, may be provided between thebottom-most patterned circuit layer 821 and the passivation layer 5,described as the polymer layer 95 shown in FIG. 3D. In FIGS. 1C, 2C and3C, the ground plane, trace or line 82 over the passivation layer 5,used to distribute a ground reference voltage of Vss, is connected tothe ground nodes Ts, Us, Vs and Ws of the internal circuits 21, 22, 23and 24 and the ground node Rs of the regulator or voltage converter 41through the openings 521, 522, 524 and 529 in the passivation layer 5and the fine-line metal structures 621, 622, 624 and 629, respectively.The power plane, trace or line 81 or 812 used to distribute a powervoltage of Vcc is connected to the power nodes Tp, Up, Vp and Wp (notshown) of the internal circuits 21, 22, 23 and 24 and to the outputnodes P of the regulator or voltage converter 41 through the openings(not shown) in the polymer layer 98 and in the passivation layer 5 andthrough the fine-line metal structures 611, 612, 614 and 619′,respectively, as illustrated in FIG. 3B.

In FIG. 3B, there is only one patterned circuit layer 811, including aportion serving as the above-mentioned thick and wide metal trace 81P,power bus or plane delivering a power voltage input from an externalcircuit, over the passivation layer 5, and another portion serving asthe above-mentioned thick and wide metal trace 81, power bus or planedelivering a power voltage output from the voltage regulator or voltageconverter 41, over the passivation layer 5. The patterned circuit layer811 may contain an adhesion/barrier layer, a seed layer on theadhesion/barrier layer, and an electroplated metal layer 8112 on theseed layer, the adhesion/barrier layer and the seed layer composing thebottom layer 8111.

Referring to FIG. 3B, regards to the process for forming the patternedcircuit layer 811, the adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on asilicon-nitride layer of the passivation layer 5 and on contact pads6490, principally made of aluminum or copper, exposed by multipleopenings 549, 511, 512 and 514 in the passivation layer 5. Thereafter,the seed layer may be formed by sputtering a copper layer having athickness between 200 and 3000 angstroms on the adhesion/barrier layerof any above-mentioned material or by sputtering a gold layer having athickness between 200 and 3000 angstroms on the adhesion/barrier layerof any above-mentioned material. Thereafter, a photoresist layer may beformed on the seed layer, multiple openings in the photoresist layerexposing the seed layer. Thereafter, the metal layer 8112 may be formedby electroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer, by electroplating a copper layerhaving a thickness between 2 and 30 micrometers on the copper layerserving as the seed layer, exposed by the openings in the photoresistlayer and then electroplating a nickel layer having a thickness between0.5 and 10 micrometers on the electroplated copper layer in the openingsin the photoresist layer, by electroplating a copper layer having athickness between 2 and 30 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer,electroplating a nickel layer having a thickness between 0.5 and 10micrometers on the electroplated copper layer in the openings in thephotoresist layer and then electroplating a gold layer, platinum layer,palladium layer or ruthenium layer having a thickness between 0.05 and 2micrometers on the electroplated nickel layer in the openings in thephotoresist layer, or by electroplating a gold layer having a thicknessbetween 2 and 30 micrometers on the gold layer serving as the seedlayer, exposed by the openings in the photoresist layer. Thereafter, thephotoresist layer may be removed. Thereafter, the seed layer not underthe metal layer 8112 is removed using a wet-etching process or using adry-etching process. Thereafter, the adhesion/barrier layer not underthe metal layer 8112 is removed using a wet-etching process or using adry-etching process.

After the patterned circuit layer 811 is formed, a polymer layer 99 canbe formed by spin-on coating a negative photosensitive polyimide layer,such as ester type, on the patterned circuit layer 811 and on thenitride layer of the passivation layer 5, exposing the spin-on coatedphotosensitive polyimide layer, developing the exposed polyimide layerand then curing the developed polyimide layer at the temperature between265 and 285° C. for a time between 30 and 240 minutes in a nitrogen oroxygen-free ambient. Thereby, an opening 9949 may be formed in thepolymer layer 99, exposing a contact pad 8110 of the patterned circuitlayer 811.

Referring to FIG. 3B, for forming a metal bump over the contact pad8110, an adhesion/barrier layer may be formed by sputtering atitanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 99 and on the contact pad 8110 exposed by the opening9919. Thereafter, the seed layer may be formed by sputtering a copperlayer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material. Thereafter, aphotoresist layer may be formed on the seed layer, multiple openings inthe photoresist layer exposing the seed layer. Thereafter, the metalbump may be formed by electroplating a copper layer having a thicknessbetween 0.5 and 10 micrometers on the copper layer serving as the seedlayer, exposed by the openings in the photoresist layer, electroplatinga nickel layer having a thickness between 0.5 and 10 micrometers on theelectroplated copper layer in the openings in the photoresist layer, andthen electroplating a tin-containing layer, such as a tin-lead alloy, atin-silver alloy or a tin-silver-copper alloy, having a thicknessbetween 60 and 200 micrometers on the electroplated nickel layer in theopenings in the photoresist layer. Thereafter, the photoresist layer maybe removed. Thereafter, the seed layer not under the metal bump isremoved using a wet-etching process or using a dry-etching process.Thereafter, the adhesion/barrier layer not under the metal bump isremoved using a wet-etching process or using a dry-etching process.Thereafter, the metal bump can be reflowed to be shaped like a ball fora flip-chip assembly. The metal bump can be connected to a printedcircuit board, ceramic substrate or another semiconductor chip.

Referring to FIG. 3B, for forming another kind of metal bump over thecontact pad 8110, an adhesion/barrier layer may be formed by sputteringa titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, or sputtering a tantalum-containing layer, such as tantalumlayer or tantalum-nitride layer, having a thickness between 1000 and6000 angstroms, on the polymer layer 99 and on the contact pad 8110exposed by the opening 9919. Thereafter, the seed layer may be formed bysputtering a gold layer having a thickness between 200 and 3000angstroms on the adhesion/barrier layer of any above-mentioned material.Thereafter, a photoresist layer may be formed on the seed layer,multiple openings in the photoresist layer exposing the seed layer.Thereafter, the metal bump may be formed by electroplating a gold layerhaving a thickness between 6 and 25 micrometers on the gold layerserving as the seed layer, exposed by the openings in the photoresistlayer. Thereafter, the photoresist layer may be removed. Thereafter, theseed layer not under the metal bump is removed using a wet-etchingprocess or using a dry-etching process. Thereafter, the adhesion/barrierlayer not under the metal bump is removed using a wet-etching process orusing a dry-etching process. The metal bump can be connected to aflexible substrate by a tape-automated bonding (TAB) process, or a glasssubstrate via anisotropic conductive film or paste (ACF or ACP).

Alternatively, referring to FIG. 3B, a nickel layer having a thicknessbetween 0.05 and 2 micrometers can be electroless plated on the contactpad 8110 exposed by the opening 9919, and a gold layer, platinum layer,palladium layer or ruthenium layer having a thickness between 0.05 and 2micrometers can be electroless plated on the electroless plated nickellayer in the opening 9919 in the polymer layer 99. Thereafter, a goldwire can be bonded onto the electroless plated gold layer in the opening9919 in the polymer layer 99 using a wirebonding process.

Alternatively, referring to FIG. 3B, a gold wire can be bonded onto agold layer, platinum layer, palladium layer or ruthenium layer of thepatterned circuit layer 811, exposed by the openings 9919 in the polymerlayer 99 using a wirebonding process.

Referring to FIG. 3D, before the patterned circuit layer 811 is formed,a polymer layer 95 can be optionally formed by spin-on coating anegative photosensitive polyimide layer, such as ester type, on thenitride layer of the passivation layer 5 and on the contact pads 6490,exposing the spin-on coated photosensitive polyimide layer, developingthe exposed polyimide layer and then curing the developed polyimidelayer at the temperature between 265 and 285° C. for a time between 30and 240 minutes in a nitrogen or oxygen-free ambient. Thereby, multipleopenings 9519, 9519′, 9511, 9512 and 9514 may be formed in the polymerlayer 95, exposing multiple contact pads 6190 exposed by the openings519, 519′, 511, 512 and 514 in the passivation layer 5. After thepolymer layer 95 is formed, the patterned circuit layer 811 can beformed on the polymer layer 95 and on the contact pads 6190 exposed bythe openings 519, 519′, 511, 512 and 514. The adhesion/barrier layer ofany above-mentioned material may be sputtered on the polymer layer 95and on the contact pads 6190 exposed by the openings 9519, 9511, 9512and 9514 in the polymer layer 95.

One of the patterned circuit layers 812 and 821 shown in FIG. 3C,composing the thick metal traces or planes 81 and 82 over thepassivation layer 5 may comprise an adhesion/barrier/seed layer 8111,and a bulk conduction metal layer 8112. The methods to form thepatterned circuit layers 812 and 821 and the specification thereof maybe based on the methods to form the patterned circuit layer 801, 802 or803 and the specification thereof shown in FIGS. 15A-15L, 16A-16L,17A-17J, 18A-18I and 19A-19I.

In FIG. 3C, the thick and wide metal trace, bus or plane 82, used todeliver a ground voltage, may have a lower patterned circuit layer underan upper patterned circuit layer of the thick and wide metal trace, busor plane 81, used to deliver a power voltage Vcc output from the voltageregulator or voltage converter 41. Alternatively, the thick and widemetal trace, bus or plane 82, used to deliver a ground voltage, may havean upper patterned circuit layer over a lower patterned circuit layer ofthe thick and wide metal trace, bus or plane 81, used to deliver a powervoltage Vcc output from the voltage regulator or voltage converter 41. Apolymer layer having a thickness between 2 and 30 micrometers may bebetween the upper and lower patterned circuit layers. Each f the lowerand upper patterned circuit layers may have an electroplated copperlayer having a thickness between 2 and 30 micrometers.

Referring to FIG. 3C, there may be multiple patterned circuit layers 821and 812, including the above-mentioned ground bus or plane 82 and theabove-mentioned power bus or plane 81, used to deliver a power voltageoutput from the voltage regulator or voltage converter 41, over theground bus or plane 82, over the passivation layer 5. The process forforming the patterned circuit layer 821 on the passivation layer 5 andon the contact pads 6290 exposed by the openings 529, 521, 522 and 524can be referred to as the process for forming the patterned circuitlayer 811 shown in FIG. 3B on the passivation layer 5 and on the contactpads 6190 exposed by the openings 519, 511, 512 and 514. The patternedcircuit layer 821 may contain an adhesion/barrier layer, a seed layer onthe adhesion/barrier layer, and an electroplated metal layer 8212 on theseed layer, the adhesion/barrier layer and the seed layer composing thebottom layer 8211. The patterned circuit layer 812 may contain anadhesion/barrier layer, a seed layer on the adhesion/barrier layer, andan electroplated metal layer 8122 on the seed layer, theadhesion/barrier layer and the seed layer composing the bottom layer8121.

Referring to FIG. 3C, after the patterned circuit layer 821 is formed, apolymer layer 98 can be formed by spin-on coating a negativephotosensitive polyimide layer, such as ester type, on the patternedcircuit layer 821 and on the nitride layer of the passivation layer 5,exposing the spin-on coated photosensitive polyimide layer, developingthe exposed polyimide layer and then curing the developed polyimidelayer at the temperature between 265 and 285° C. for a time between 30and 240 minutes in a nitrogen or oxygen-free ambient. Thereby, anopening 9829 may be formed in the polymer layer 98, exposing a contactpad of the patterned circuit layer 821.

Referring to FIG. 3C, regards to the process for forming the patternedcircuit layer 812, the adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 98 and on the contact pad of the patterned circuit layer821 exposed by the opening 9829 in the polymer layer 98. Thereafter, theseed layer may be formed by sputtering a copper layer having a thicknessbetween 200 and 3000 angstroms on the adhesion/barrier layer of anyabove-mentioned material or by sputtering a gold layer having athickness between 200 and 3000 angstroms on the adhesion/barrier layerof any above-mentioned material. Thereafter, a photoresist layer may beformed on the seed layer, multiple openings in the photoresist layerexposing the seed layer. Thereafter, the metal layer 8122 may be formedby electroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer, by electroplating a copper layerhaving a thickness between 2 and 30 micrometers on the copper layerserving as the seed layer, exposed by the openings in the photoresistlayer and then electroplating a nickel layer having a thickness between0.5 and 10 micrometers on the electroplated copper layer in the openingsin the photoresist layer, by electroplating a copper layer having athickness between 2 and 30 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer,electroplating a nickel layer having a thickness between 0.5 and 10micrometers on the electroplated copper layer in the openings in thephotoresist layer and then electroplating a gold layer, platinum layer,palladium layer or ruthenium layer having a thickness between 0.05 and 2micrometers on the electroplated nickel layer in the openings in thephotoresist layer, or by electroplating a gold layer having a thicknessbetween 2 and 30 micrometers on the gold layer serving as the seedlayer, exposed by the openings in the photoresist layer. Thereafter, thephotoresist layer may be removed. Thereafter, the seed layer not underthe metal layer 8122 is removed using a wet-etching process or using adry-etching process. Thereafter, the adhesion/barrier layer not underthe metal layer 8122 is removed using a wet-etching process or using adry-etching process.

After the patterned circuit layer 812 is formed, a polymer layer 99 canbe formed by spin-on coating a negative photosensitive polyimide layer,such as ester type, on the patterned circuit layer 812 and on thepolymer layer 98, exposing the spin-on coated photosensitive polyimidelayer, developing the exposed polyimide layer and then curing thedeveloped polyimide layer at the temperature between 265 and 285° C. fora time between 30 and 240 minutes in a nitrogen or oxygen-free ambient.Thereby, an opening 9929 may be formed in the polymer layer 99, exposinga contact pad 8120 of the patterned circuit layer 812.

Referring to FIG. 3C, for forming a metal bump over the contact pad8120, an adhesion/barrier layer may be formed by sputtering atitanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 99 and on the contact pad 8120 exposed by the opening9929. Thereafter, the seed layer may be formed by sputtering a copperlayer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material. Thereafter, aphotoresist layer may be formed on the seed layer, multiple openings inthe photoresist layer exposing the seed layer. Thereafter, the metalbump may be formed by electroplating a copper layer having a thicknessbetween 0.5 and 10 micrometers on the copper layer serving as the seedlayer, exposed by the openings in the photoresist layer, electroplatinga nickel layer having a thickness between 0.5 and 10 micrometers on theelectroplated copper layer in the openings in the photoresist layer, andthen electroplating a tin-containing layer, such as a tin-lead alloy, atin-silver alloy or a tin-silver-copper alloy, having a thicknessbetween 60 and 200 micrometers on the electroplated nickel layer in theopenings in the photoresist layer. Thereafter, the photoresist layer maybe removed. Thereafter, the seed layer not under the metal bump isremoved using a wet-etching process or using a dry-etching process.Thereafter, the adhesion/barrier layer not under the metal bump isremoved using a wet-etching process or using a dry-etching process.Thereafter, the metal bump can be reflowed to be shaped like a ball. Themetal bump can be connected to a printed circuit board, ceramicsubstrate or another semiconductor chip.

Referring to FIG. 3C, for forming another kind of metal bump over thecontact pad 8120, an adhesion/barrier layer may be formed by sputteringa titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, or sputtering a tantalum-containing layer, such as tantalumlayer or tantalum-nitride layer, having a thickness between 1000 and6000 angstroms, on the polymer layer 99 and on the contact pad 8120exposed by the opening 9929. Thereafter, the seed layer may be formed bysputtering a gold layer having a thickness between 200 and 3000angstroms on the adhesion/barrier layer of any above-mentioned material.Thereafter, a photoresist layer may be formed on the seed layer,multiple openings in the photoresist layer exposing the seed layer.Thereafter, the metal bump may be formed by electroplating a gold layerhaving a thickness between 6 and 25 micrometers on the gold layerserving as the seed layer, exposed by the openings in the photoresistlayer. Thereafter, the photoresist layer may be removed. Thereafter, theseed layer not under the metal bump is removed using a wet-etchingprocess or using a dry-etching process. Thereafter, the adhesion/barrierlayer not under the metal bump is removed using a wet-etching process orusing a dry-etching process. The metal bump can be connected to aflexible substrate by a tape-automated bonding (TAB) process, or a glasssubstrate via anisotropic conductive film or paste (ACF or ACP).

Alternatively, referring to FIG. 3C, a nickel layer having a thicknessbetween 0.05 and 2 micrometers can be electroless plated on the contactpad 8120 exposed by the opening 9929 in layer polymer layer 99, and agold layer, platinum layer, palladium layer or ruthenium layer having athickness between 0.05 and 2 micrometers can be electroless plated onthe electroless plated nickel layer in the opening 9929 in the polymerlayer 99. Thereafter, a gold wire can be bonded onto the electrolessplated gold layer in the opening 9929 in the polymer layer 99 using awirebonding process.

Alternatively, referring to FIG. 3C, a gold wire can be bonded onto agold layer, platinum layer, palladium layer or ruthenium layer of thepatterned circuit layer 812, exposed by the openings 9929 in the polymerlayer 99 using a wirebonding process.

Alternatively, before the patterned circuit layer 821 is formed, apolymer layer can be optionally formed by spin-on coating a negativephotosensitive polyimide layer, such as ester type, on the nitride layerof the passivation layer 5 and on the contact pads 6290, exposing thespin-on coated photosensitive polyimide layer, developing the exposedpolyimide layer and then curing the developed polyimide layer at thetemperature between 265 and 285° C. for a time between 30 and 240minutes in a nitrogen or oxygen-free ambient. Thereby, multiple openingsmay be formed in the polymer layer, exposing multiple contact pads 6290exposed by the openings 529, 521, 522 and 524 in the passivation layer5. After the polymer layer is formed, the patterned circuit layer 821can be formed on the polymer layer and on the contact pads 6290 exposedby the openings 529, 521, 522 and 524. The adhesion/barrier layer of anyabove-mentioned material may be sputtered on the polymer layer and onthe contact pads 6290 exposed by the openings in the polymer layer.

In some applications, some metal lines, traces or planes used totransmit a digital signal or analog signal can be provided on thepolymer layer 98 and at the same level as the power traces, buses orplanes 812. Alternatively, some metal lines, traces or planes used totransmit a digital signal or analog signal can be provided on thepassivation layer 5 and at the same level as the ground traces, buses orplanes 82. There are more other structures formed over the passivationlayer 5, described as below: (1) in the first application for highperformance circuits or high precision analog circuits, anotherpatterned circuit layer, such as signal planes, buses, traces or lines,used to transmit a digital signal or an analog signal (not shown) may beadded between the power lines, buses or planes 812 and the ground lines,buses or planes 821. Polymer layers, such as polyimide, benzocyclobutene(BCB), parylene, epoxy-based material, photoepoxy SU-8, elastomer orsilicone, (not shown) over and under the signal planes, buses, traces orlines are provided to separate the signal planes, buses, traces or linesfrom the power traces, buses or planes 812 and to separate the signalplanes, buses, traces or lines from the ground traces, buses or planes821, respectively; (2) in the second application of the high current orthe high precision circuit, another patterned circuit layer, such asground planes, buses, traces or lines, (not shown) used to distribute aground reference voltage may be added over the power traces, buses orplanes 812. The power traces, buses or planes 812 are sandwiched by theground traces, buses or planes 821 under the power traces, buses orplanes 812 and the newly-added ground traces, buses or planes over thepower traces, buses or planes 812, therefore, forming a Vss/Vcc/Vssstructure (the stack is from the bottom to the top) over the passivationlayer 5. A polymer layer, such as polyimide, benzocyclobutene (BCB),parylene, epoxy-based material, photoepoxy SU-8, elastomer or silicone,having a thickness of between 2 and 30 microns, is provided between thenewly-added ground planes, buses, traces or lines and the power traces,buses or planes 812. A cap polymer layer, such as polyimide,benzocyclobutene (BCB), parylene, epoxy-based material, photoepoxy SU-8,elastomer or silicone, having a thickness of between 2 and 30 microns,covers the newly-added ground planes, buses, traces or lines; (3) in thethird application of the high current or the high precision circuit, ifrequired, based on the second application of the Vss/Vcc/Vss structure,another patterned circuit layer, such as power planes, buses, traces orlines, (not shown) used to distribute a power voltage can be furtherformed over the top ground planes, buses, traces or lines (not shown)over the power traces, buses or planes 812, creating a Vss/Vcc/Vss,/Vccstructure, (the stack is from the bottom to the top) over thepassivation layer 5. A polymer layer, such as polyimide,benzocyclobutene (BCB), parylene, epoxy-based material, photoepoxy SU-8,elastomer or silicone, having a thickness of between 2 and 30 microns,is provided between the newly-added power planes, buses, traces or linesand the top ground traces, buses or planes 81. A cap polymer layer, suchas polyimide, benzocyclobutene (BCB), parylene, epoxy-based material,photoepoxy SU-8, elastomer or silicone, having a thickness of between 2and 30 microns, covers the newly-added power planes, buses, traces orlines. The above-mentioned structures provide a robust power supply forhigh current circuits, high precision analog circuits, high speedcircuits, low power circuits, power management circuits, and highperformance circuits.

FIG. 4 shows a circuit design for the regulator or voltage converter 41in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D. This circuit design is for avoltage regulator or converter 41 usually used in the modern DRAM designas described in “Semiconductor Memories: A handbook of Design,Manufacture and Application” Second Edition, By B. Prince, published byJohn Wiley & Sons, 1991. The voltage regulator or converter 41 shown inFIG. 4 provides both voltage regulating function and voltage convertingfunction. The external voltage Vdd can be converted to an output voltageVcc varying at a desired voltage level Vcc0, and the ratio of thedifference of between Vcc and Vcc0 to Vcc0 is less than 10%, andpreferably less than 5%. As discussed in the section of “description ofrelated arts”, more modern IC chips require on-chip voltage convertersto convert the external (system, board, module, or card level) powersupply voltage to a voltage level required by the chip. Moreover, somechips, such as a DRAM chip, even require dual or even triple voltagelevels on the same chip: for example, 3.3 V for peripheral controlcircuits, while 1.5 V for the memory cells in the cell array area.

The voltage regulator or converter 41 in FIG. 4 comprises two circuitblocks: a voltage reference generator 410 and a current mirror circuit410′. The voltage reference generator 410 generates a reference voltageV_(R) at the node R, insensitive to the voltage fluctuation of theexternal power supply voltage Vdd at node 4199. Vdd is also the inputsupply voltage of the reference voltage generator 410. The voltagereference generator 410 comprises two paths of voltage divider. One pathcomprises three p-channel MOS transistors, 4101, 4103 and 4105 connectedin series, and the other path comprises two p-channel MOS transistors4102 and 4104 connected in series. With the drain of the MOS transistor4103 coupled to the gate of the MOS transistor 4104, the outputreference voltage V_(R) is regulated. When Vdd is fluctuated with arise, the voltage level at node G will rise, resulting in a weakerturn-on of the MOS transistor 4104. When the MOS transistor 4104 isturned-on weaker, V_(R) drops or rises with a smaller extent. Similarly,V_(R) rises or drops with a smaller extent, when Vdd is fluctuated witha drop. This explains the voltage regulation behavior of the voltagereference generator 410. The output of the voltage reference generator410is used as a reference voltage of the current mirror circuit 410′.The current mirror circuit 410′ provides a power supply with voltage ata desired constant level and with large current capability for an ICchip. The current mirror circuit 410′ also eliminates possible hugepower consumption or waste by avoiding a direct high current path fromVdd to Vss in the paths of voltage dividers. With the drain of thep-channel MOS transistor 4109 coupled to the gate of the outputp-channel MOS transistor 4106, and with the output voltage node Pcoupled to the gate of the reference-voltage-mirror p-channel MOStransistor 4110, the output voltage Vcc is regulated, and thereby theoutput voltage level Vcc can be designed at a desired level. Theconductance transistor 4112 is a small p-channel MOS transistor with agate connected to Vss, hence the transistor 4112 is always turned on.The conductance transistor 4111 is a large p-channel MOS, and its gateis controlled by a signal Φ. The transistor 4111 is turned on when theinternal circuits or internal circuit units are in an active cycle,resulting in a fast response of the current path provided by thep-channel MOS transistor 4109 and n-channel MOS transistor 4107, and ofthe current path provided by the p-channel MOS transistor 4110 andn-channel MOS transistor 4108. The turn-on of the transistor 4111minimizes the output supply Vcc bounce caused by a large transientcurrent demanded by the internal circuits, such as 21, 22, 23 and 24,shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D. When the internal circuitsor internal circuit units are in idle cycle, the transistor 4111 isturned off to save power consumption.

Second Embodiment Over-Passivation Interconnection for Internal Circuits

The coarse traces over the passivation layer 5 described in the firstembodiment can be alternatively used as an interconnection of ICinternal circuits to transmit a signal from an internal circuit toanother one or other ones. In this application, the coarse metalconductor over a passivation layer is used to transmit a signal or datafrom an output node Xo of an internal circuit 21 to input nodes Ui, Viand Wi of other internal circuits 22, 23 and 24, as shown in FIG. 5B.When designed as a bundle of metal lines or metal traces that connects aset of similar nodes for inputting or outputting data signals, bitsignals or address signals, for example, between two internal functionalcircuits separated in a longer distance (for example, in the distance of1 mm or more 500 microns), such as the 8-, 16-, 32-, 64-, 128-, 256−,512-, or 1024-bits of data (or address) connection between a processorunit and a memory unit on the same chip, the lines or traces are oftenreferred to as buses, such as word buses or bit buses used in a memory.For these applications, the invention provides a thick metal trace, busor plane 83 over a passivation layer 5, far away from underlying MOSdevices, to connect multiple internal circuits 21, 22, 23 and 24, asshown in FIG. 5B, and thereby allows the electrical signal to pass overMOS devices without perturbing the underlying MOS devices and withoutsignificant degradation of signal integrity. It is noted that the thickmetal trace, bus or plane 83 over the passivation layer 5 connects thenodes of the internal circuits 21, 22, 23 and 24 not through anyoff-chip input/output circuit connected with an external circuit, and isnot connected up to an external circuit. As the above-mentioned thickmetal trace, bus or plane 83 over the passivation layer 5 may induceonly very low parasitic capacitance, the signal passing through thethick metal trace, bus or plane 83 will not be dramatically degraded. Itmakes this invention very suitable for high-speed, low power, highcurrent or low voltage applications. In most cases of this invention, noadditional amplifier, driver/receiver or repeater is required to helpsustain the integrity of the signal passing through the thick metaltrace, bus or plane 83. In some cases of this invention, an internaldriver, internal receiver, internal tri-state buffer, or repeater,comprising MOS transistors with a smaller size as compared to those ofthe off-chip circuits connected with an external circuit, is required totransmit a signal passing through a long path, such as the thick metaltrace, bus or plane 83 having a length of greater than 500 microns orgreater than 1000 microns.

FIGS. 5B, 6B, and 7B show the second preferred embodiment of theinvention. FIG. 5B shows a simplified circuitry diagram where apatterned metal trace, bus or plane 83 over a passivation layer 5connects multiple internal circuits 21, 22, 23 and 24 to transmit asignal from an output node Xo of an internal circuit 21 to input nodesUi, Vi and Wi of the internal circuits 22, 23 and 24. FIG. 6B shows atop view of the semiconductor chip realizing the circuitry shown in FIG.5B, wherein coarse traces 83 shown in FIG. 6B indicate the traces formedover the passivation layer 5, and fine traces 632 a, 632 b and 632 cshown in FIGS. 6B indicate the traces formed under the passivation layer5. FIG. 7B shows a cross-sectional view of the semiconductor chipsrealizing the circuitry shown in FIG. 5B. FIG. 6B shows a top view ofthe semiconductor chip shown in FIG. 7B, wherein the patterned circuitlayer 831, such as a signal plane, bus, trace or line, to transmit asignal from the internal circuit 21 to the internal circuits 22, 23 and24 is realized from the concept of the coarse trace 83 shown in FIGS. 5Band 6B. As shown in FIGS. 5B, 6B and 7B, the internal circuit 21includes an input node Xi to receive a signal and an output node Xo tooutput an electrical signal to the internal circuits 22, 23 and 24. Theinternal circuit 21 can be a logic gate, such as inverter, NOR gate,NAND gate, OR gate, AND gate, or an internal buffer (an inverter, aninternal driver, or an internal tri-state buffer, shown in FIGS. 5C, 5D,and 5E, respectively). Through the coarse metal scheme 83 over thepassivation layer 5, the input nodes Ui, Vi and Wi of the internal logiccircuits 22, 23 and 24 (two NOR gates 22 and 24, and one NAND gate 23)are able to receive data or signal sent from the internal circuit 21.The voltage level at input nodest Ui, Vi and Wi are between Vdd andV_(ss) with very minimal degradation and noise in that theinterconnecting metal trace or bus 83 over the passivation layer 5 haslow resistance and create low capacitance. It is noted that in thisdesign the thick metal trace or bus 83 is not connected to off-chipcircuits connected to an external circuit, such as ESD circuit, off-chipdriver, off-chip receiver, or off-chip tri-state buffer circuit,resulting in speed improvement and power consumption reduction.

Referring to FIGS. 5A, 6A and 7A showing the prior art to illustrate howthe internal circuits 21, 22, 23 and 24 are connected. The prior artrelies on the fine-line metal traces 63, comprising segments of 6311,6321, 6341 and 638, under the passivation layer 5 to pass data outputfrom the internal circuit 21 to the internal circuits 22, 23 and 24,without relying on any patterned circuit layer over the passivationlayer 5. The design of prior art results in signal degradation,performance reduction, high power consumption, and high heat generationbecause it is difficult to form a thick metal trace under thepassivation layer 5.

FIGS. 5B and 6B reveal that the coarse metal scheme 83 is built over thepassivation layer 5 of the 1C chip, and is connected to the internalcircuits 21, 22, 23 and 24. FIGS. 5A, 6A and 7A show that, in a priorart, the internal circuit 21 is connected to a NOR gate 22 throughsegments 6311, 638, 6321 a and 6321 b of the fine-line metal structuresunder the passivation layer 5, to a NAND gate 23 through segments 6311,638, 6321 a and 6321 c of the fine-line metal structures under thepassivation layer 5, and to another NOR gate 24 through segments 6311,638 and 6341 of the fine-line metal structures under the passivationlayer 5. In the present invention, the second segment 638 of thefine-line metal structure is replaced by a coarse metal conductor 83over the passvation layer 5, as shown in FIGS. 5B and 6B. A signaloutput from an output node (usually the drain of a MOS transistor in theinternal circuit 21) of the internal circuit 21 may pass through asegment 631 of the fine-line metal structure under the passivation layer5, then through an opening 531 in the passivation layer 5, then throughthe interconnection scheme 83 over the passivation layer 5, then throughan opening 534 in the passivation layer 5, then through a segment 634 ofthe fine-line metal structure under the passivation layer 5, and then toan input node (usually the gate of an MOS transistor in the NOR gate 24)of the NOR gate 24. A signal output from an output node (usually thedrain of an MOS transistor in the internal circuit 21) of the internalcircuit 21 may pass through a segment 631 of the fine-line metalstructure under the passivation layer 5, then through the opening 531 inthe passivation layer 5, then through the interconnection scheme 83 overthe passivation layer 5, then through an opening 532 in the passivationlayer 5, then through a segment 632 a and a segment 632 b or 632 c ofthe fine-line metal interconnection scheme under the passivation layer5, and then to the input nodes (usually the gates of MOS transistors inthe NOR gate 22 and the NAND gate 23, respectively) of a NOR gate 22 anda NAND gate 23.

Alternatively, when the internal circuit 21 is a NOR gate, the internalcircuits 22, 23 and 24 may be NOR gates, OR gates, NAND gate or ANDgates. When the internal circuit 21 is an OR gate, the internal circuits22, 23 and 24 may be NOR gates, OR gates, NAND gate or AND gates. Whenthe internal circuit 21 is a NAND gate, the internal circuits 22, 23 and24 may be NOR gates, OR gates, NAND gate or AND gates. When the internalcircuit 21 is a AND gate, the internal circuits 22, 23 and 24 may be NORgates, OR gates, NAND gate or AND gates. When a NMOS transistor in theinternal circuit 21 having a drain as the output node Xo of the internalcircuit 21 has a ratio of a physical channel width thereof to a physicalchannel length thereof ranging from 0.1 to 20, ranging from 0.1 to 10,or preferably ranging from 0.2 to 2, a NMOS transistor in the internalcircuit 22, 23 or 24 having a gate as the input node Ui, Vi and Wi ofthe internal circuit 22, 23 or 24 has a ratio of a physical channelwidth thereof to a physical channel length thereof ranging from 0.1 to20, ranging from 0.1 to 10 or preferably ranging from 0.2 to 2. When aNMOS transistor in the internal circuit 21 having a drain as the outputnode Xo of the internal circuit 21 has a ratio of a physical channelwidth thereof to a physical channel length thereof ranging from 0.1 to20, ranging from 0.1 to 10, or preferably ranging from 0.2 to 2, a PMOStransistor in the internal circuit 22, 23 or 24 having a gate as theinput node Ui, Vi and Wi of the internal circuit 22, 23 or 24 has aratio of a physical channel width thereof to a physical channel lengththereof ranging from 0.2 to 40, ranging from 0.2 to 20, or preferablyranging from 0.4 to 4. When a PMOS transistor in the internal circuit 21having a drain as the output node Xo of the internal circuit 21 has aratio of a physical channel width thereof to a physical channel lengththereof ranging from 0.2 to 40, ranging from 0.2 to 20, or preferablyranging from 0.4 to 4, a NMOS transistor in the internal circuit 22, 23or 24 having a gate as the input node Ui, Vi and Wi of the internalcircuit 22, 23 or 24 has a ratio of a physical channel width thereof toa physical channel length thereof ranging from 0.1 to 20, ranging from0.1 to 10, or preferably ranging from 0.2 to 2. When a PMOS transistorin the internal circuit 21 having a drain as the output node Xo of theinternal circuit 21 has a ratio of a physical channel width thereof to aphysical channel length thereof ranging from 0.2 to 40, ranging from 0.2to 20, or preferably ranging from 0.4 to 4, a PMOS transistor in theinternal circuit 22, 23 or 24 having a gate as the input node Ui, Vi andWi of the internal circuit 22, 23 or 24 has a ratio of a physicalchannel width thereof to a physical channel length thereof ranging from0.2 to 40, ranging from 0.2 to 20, or preferably ranging from 0.4 to 4.In the above-mentioned case, a signal output from the output node Xo ofthe internal circuit 21 may pass through the thick metal plane, bus,trace or line 83 to the internal circuits 22, 23 and 24, with a current,passing through the thick metal plane, bus, trace or line 83, rangingfrom 50 microamperes to 2 milliamperes, and preferably ranging from 100microamperes to 1 milliampere. The fine line metal structures 634, 632and 631 shown in 7B, 7C and 7D may be formed with multiple circuitlayers 60 and multiple stacked plugs 60′, upper plugs 60′ being alignedwith bottom plugs 60′. When the circuit layers 60 are formed withelectroplated copper, the stacked plugs 60′ may be formed withelectroplated copper. When the circuit layers 60 are formed withsputtered aluminum, the stacked plugs 60′ may be formed with chemicalvapor deposited tungsten. There are multiple insulating layers 30 underthe passivation layer 5, and each one is positioned between theneighboring two of the circuit layers 60. The insulating layers 30 madeof one or more inorganic materials may include a layer of silicon oxidewith a thickness of between 0.01 and 2 micrometers, may include a layerof fluroine doped silicate glass (FSG) with a thickness of between 0.01and 2 micrometers, or may include a layer with a lower dielectricconstant, such as between 1.5 and 3.5, having a thickness of between0.01 and 2 micrometers, such as black diamond film or a materialcontaining hydrogen, carbon, oxygen and silicon.

The thick metal trace or plane 83 over the passivation layer 5, shown inFIG. 5B and 6B, may be composed of only one patterned circuit layer 831,as shown in FIG. 7B, or multiple patterned circuit layers 831 and 832,as shown in FIG. 7C. In FIG. 7B, the patterned circuit layer 831, suchas a signal plane, bus, trace or line, to transmit a signal is realizedfrom the concept of the coarse trace 83 shown in FIGS. 5B and 6B. InFIG. 7C, the patterned circuit layers 831 and 832, such as signalplanes, buses, traces or lines, to transmit a signal is realized fromthe concept of the coarse trace 83 shown in FIGS. 5B and 6B. When thethick metal traces or plane 83 over the passivation layer 5, shown inFIGS. 5B and 6B, is composed of multiple patterned circuit layers 831and 832, as shown in FIG. 7C, a polymer layer 98, such as polyimide(PI), benzocyclobutene (BCB), parylene, photoepoxy SU-8, epoxy-basedmaterial, elastomer or silicone, may be between the neighboringpatterned circuit layers 831 and 832, separating the patterned circuitlayers 831 and 832. The polymer layer 98 may have a thickness between 2and 30 micrometers. A polymer layer 99, such as polyimide (PI),benzocyclobutene (BCB), parylene, epoxy-based material, photoepoxy SU-8,elastomer or silicone, may be on the topmost one 832 of the patternedcircuit layers 831 and 832, separated by the above mentioned polymerlayers 98, over the passivation layer 5, as shown in FIG. 7C, or on theonly one patterned circuit layer 831, as shown in FIGS. 7B and 7D. Thepolymer layer 99 may have a thickness between 2 and 30 micrometers. Itis noted that no opening in the polymer layer 99 expose the patternedcircuit layer 831 or 832, and the patterned circuit layer 831 or 832 hasno pad connected up to an external circuit, as shown in FIGS. 7B, 7C and7D. Alternatively, a polymer layer 95, such as polyimide (PI),benzocyclobutene (BCB), parylene, epoxy-based material, photoepoxy SU-8,elastomer or silicone, may be between the passivation layer 5 and thebottommost one 831 of the patterned circuit layers 831 and 832,separated by the above mentioned polymer layers 98, for the structureshown in FIG. 7C, or between the passivation layer 5 and the only onepatterned circuit layer 831, as shown in FIG. 7D. The polymer layer 95may have a thickness between 2 and 30 micrometers. Multiple openings9519, 9519′, 9511, 9512 and 9514 in the polymer layer 95 aresubstantially aligned with the openings 519, 519′, 511, 512 and 514 inthe passivation layer 5, respectively. The openings 9531, 9532 and 9534in the polymer layer 95 expose the pads exposed by the openings 531, 532and 534 in the passivation layer 5, respectively.

The openings 9531, 9532 and 9534 in the polymer layer 95 have lowerportions having widths or transverse dimensions greater than those ofthe openings 531, 532 and 534 in the passivation layer 5 aligned withthe openings 9531, 9532 and 9534, respectively. The openings 9531, 9532and 9534 in the polymer layer 95 further expose the passivation layer 5close to the openings 531, 532 and 534. The shape of the openings 531,532 and 534 from a top perspective view may be round, square,rectangular or polygon. If the openings 531, 532 and 534 are round, theopenings 531, 532 and 534 may have a diameter of between 0.1 and 200microns, between 1 and 100 microns, or, preferably, between 0.1 and 30microns. If the openings 531, 532 and 534 are square, the openings 531,532 and 534 may have a width of between 0.1 and 200 microns, between 1and 100 microns, or, preferably, between 0.1 and 30 microns. If theopenings 531, 532 and 534 are rectangular, the openings 531, 532 and 534may have a width of between 0.1 and 200 microns, between 1 and 100microns, or, preferably, between 0.1 and 30 microns, and a length ofbetween 1 micron and 1 centimeter. If the openings 531, 532 and 534 arepolygon having more than five sides, the openings 531, 532 and 534 havea greatest diagonal length of between 0.1 and 200 microns, between 1 and100 microns, or, preferably, between 0.1 and 30 microns. Alternatively,the openings 531, 532 and 534 have a greatest transverse dimension ofbetween 0.1 and 200 microns, between 1 and 100 microns, or, preferably,between 0.1 and 30 microns. In a case, the openings 531, 532 and 534have a width of between 0.1 and 30 microns, with the lower portion ofthe openings 9531, 9532 and 9514 in the polymer layer 95 having a widthof between 20 and 100 microns.

Each of the patterned circuit layers 831 and 832 composing the thickmetal trace or plane 83 over the passivation layer 5, shown in FIGS. 7B,7C and 7D, may comprise an adhesion/barrier/seed layer 8311, 8311 a,8311 b or 8321 and a bulk conduction metal layer 8112, 8312 a, 8312 b or8322. The methods to form the patterned circuit layer 831 or 832 and thespecification thereof may follow the methods to form the patternedcircuit layer 801, 802 or 803 and the specification thereof shown inFIGS. 15A-15L, 16A-16L, 17A-17J, 18A-18I and 19A-191.

In FIGS. 7B and 7D, there is only one patterned circuit layer 831,including a portion serving as the above-mentioned thick and wide metaltrace 83 over the passivation layer 5. The patterned circuit layer 831may contain an adhesion/barrier layer, a seed layer on theadhesion/barrier layer, and an electroplated metal layer 8312 on theseed layer, the adhesion/barrier layer and the seed layer composing thebottom layer 8311.

Referring to FIG. 7B, regards to the process for forming the patternedcircuit layer 831, the adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on asilicon-nitride layer of the passivation layer 5 and on contact pads6390, principally made of aluminum or copper, exposed by multipleopenings 531, 532 and 534 in the passivation layer 5. Thereafter, theseed layer may be formed by sputtering a copper layer having a thicknessbetween 200 and 3000 angstroms on the adhesion/barrier layer of anyabove-mentioned material or by sputtering a gold layer having athickness between 200 and 3000 angstroms on the adhesion/barrier layerof any above-mentioned material. Thereafter, a photoresist layer may beformed on the seed layer, multiple openings in the photoresist layerexposing the seed layer. Thereafter, the metal layer 8312 may be formedby electroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer, by electroplating a copper layerhaving a thickness between 2 and 30 micrometers on the copper layerserving as the seed layer, exposed by the openings in the photoresistlayer and then electroplating a nickel layer having a thickness between0.5 and 10 micrometers on the electroplated copper layer in the openingsin the photoresist layer, by electroplating a copper layer having athickness between 2 and 30 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer,electroplating a nickel layer having a thickness between 0.5 and 10micrometers on the electroplated copper layer in the openings in thephotoresist layer and then electroplating a gold layer, platinum layer,palladium layer or ruthenium layer having a thickness between 0.05 and 2micrometers on the electroplated nickel layer in the openings in thephotoresist layer, or by electroplating a gold layer having a thicknessbetween 2 and 30 micrometers on the gold layer serving as the seedlayer, exposed by the openings in the photoresist layer. Thereafter, thephotoresist layer may be removed. Thereafter, the seed layer not underthe metal layer 8312 is removed using a wet-etching process or using adry-etching process. Thereafter, the adhesion/barrier layer not underthe metal layer 8312 is removed using a wet-etching process or using adry-etching process.

After the patterned circuit layer 831 is formed, a polymer layer 99 canbe formed by spin-on coating a negative photosensitive polyimide layer,such as ester type, on the patterned circuit layer 831 and on thenitride layer of the passivation layer 5 and then curing the spin-oncoated polyimide layer at the temperature between 265 and 285° C. for atime between 30 and 240 minutes in a nitrogen or oxygen-free ambient. Noopening is formed in the polymer layer 99 to expose the thick and widemetal trace 83.

Referring to FIG. 7D, before the patterned circuit layer 831 is formed,a polymer layer 95 can be optionally formed by spin-on coating anegative photosensitive polyimide layer, such as ester type, on thenitride layer of the passivation layer 5 and on the contact pads exposedby the openings 531, 532 and 534 in the passivation layer 5, exposingthe spin-on coated photosensitive polyimide layer, developing theexposed polyimide layer and then curing the developed polyimide layer atthe temperature between 265 and 285° C. for a time between 30 and 240minutes in a nitrogen or oxygen-free ambient. Thereby, multiple openings9531, 9532 and 9534 may be formed in the polymer layer 95, exposingmultiple contact pads exposed by the openings 531, 532 and 533 in thepassivation layer 5. After the polymer layer 95 is formed, the patternedcircuit layer 831 can be formed on the polymer layer 95 and on thecontact pads exposed by the openings 531, 532 and 533. Theadhesion/barrier layer of any above-mentioned material may be sputteredon the polymer layer 95 and on the contact pads exposed by the openings9531, 9532 and 9534 in the polymer layer 95.

Alternatively, referring to FIG. 7C, there may be multiple patternedcircuit layers 831 and 832, including a portion serving as theabove-mentioned thick and wide metal trace 83, over the passivationlayer 5. The process for forming the patterned circuit layer 831 shownin FIG. 7C can be referred to as the process for forming the patternedcircuit layer 831 shown in FIG. 10B. The patterned circuit layer 832 maycontain an adhesion/barrier layer, a seed layer on the adhesion/barrierlayer, and an electroplated metal layer 8322 on the seed layer, theadhesion/barrier layer and the seed layer composing the bottom layer8321.

Referring to FIG. 7C, after the patterned circuit layer 831 is formed, apolymer layer 98 can be formed by spin-on coating a negativephotosensitive polyimide layer, such as ester type, on the patternedcircuit layer 831 and on the nitride layer of the passivation layer 5,exposing the spin-on coated photosensitive polyimide layer, developingthe exposed polyimide layer and then curing the developed polyimidelayer at the temperature between 265 and 285° C. for a time between 30and 240 minutes in a nitrogen or oxygen-free ambient. Thereby, multipleopenings 9831 and 9834 may be formed in the polymer layer 98, exposingmultiple contact pads of the patterned circuit layer 831.

Referring to FIG. 7C, regards to the process for forming the patternedcircuit layer 832, the adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 98 and on the contact pads of the patterned circuit layer831 exposed by multiple openings 9831 and 9834 in the polymer layer 98.Thereafter, the seed layer may be formed by sputtering a copper layerhaving a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material or by sputteringa gold layer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material. Thereafter, aphotoresist layer may be formed on the seed layer, multiple openings inthe photoresist layer exposing the seed layer. Thereafter, the metallayer 8322 may be formed by electroplating a copper layer having athickness between 2 and 30 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer, byelectroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer and then electroplating a nickellayer having a thickness between 0.5 and 10 micrometers on theelectroplated copper layer in the openings in the photoresist layer, byelectroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer, electroplating a nickel layerhaving a thickness between 0.5 and 10 micrometers on the electroplatedcopper layer in the openings in the photoresist layer and thenelectroplating a gold layer, platinum layer, palladium layer orruthenium layer having a thickness between 0.05 and 2 micrometers on theelectroplated nickel layer in the openings in the photoresist layer, orby electroplating a gold layer having a thickness between 2 and 30micrometers on the gold layer serving as the seed layer, exposed by theopenings in the photoresist layer. Thereafter, the photoresist layer maybe removed. Thereafter, the seed layer not under the metal layer 8322 isremoved using a wet-etching process or using a dry-etching process.Thereafter, the adhesion/barrier layer not under the metal layer 8322 isremoved using a wet-etching process or using a dry-etching process.

After the patterned circuit layer 832 is formed, a polymer layer 99 canbe formed by spin-on coating a negative photosensitive polyimide layer,such as ester type, on the patterned circuit layer 832 and on thepolymer layer 98, and then curing the spin-on coated polyimide layer atthe temperature between 265 and 285° C. for a time between 30 and 240minutes in a nitrogen or oxygen-free ambient.

Alternatively, referring to FIG. 7C, before the patterned circuit layer831 is formed, a polymer layer 95 as mentioned in FIG. 7D can beoptionally formed by spin-on coating a negative photosensitive polyimidelayer, such as ester type, on the nitride layer of the passivation layer5 and on the contact pads exposed by the openings 531, 532 and 534 inthe passivation layer 5, exposing the spin-on coated photosensitivepolyimide layer, developing the exposed polyimide layer and then curingthe developed polyimide layer at the temperature between 265 and 285 °C. for a time between 30 and 240 minutes in a nitrogen or oxygen-freeambient. Thereby, multiple openings 9531, 9532 and 9534 may be formed inthe polymer layer 95 as mentioned in FIG. 7D, exposing multiple contactpads exposed by the openings 531, 532 and 533 in the passivation layer5. After the polymer layer 95 is formed, the patterned circuit layer 831can be formed on the polymer layer 95 and on the contact pads exposed bythe openings 531, 532 and 533. The adhesion/barrier layer of anyabove-mentioned material may be sputtered on the polymer layer 95 and onthe contact pads exposed by the openings 9531, 9532 and 9534 in thepolymer layer 95.

FIG. 7C is similar to FIG. 7B except the thick metal planes, buses ortraces 83 are composed of two patterned circuit layers 831 and 832; thebottom one is composed of segments 831 a and 831 b. A polymer layer 98separates the patterned circuit layer 831 from the patterned circuitlayer 832. In FIG. 7C, the thick metal plane, trace or bus 831 in FIG.7B is replaced by the thick metal plane, trace or bus 831 a, 831 b and832. Referring to FIG. 7C, a signal output from the output node (usuallythe drain of an MOS transistor in the internal circuit 21) of theinternal circuit 21 passes through the fine-line metal buses or traces631 under the passivation layer 5, then through the opening 531 in thepassivation layer 5, then through the metal trace or bus 831 b over thepassivation layer 5, (1) in a first path, then up through an opening9831 in the polymer layer 98, then through the metal bus or trace 832 onthe polymer layer 98, then down through an opening 9834 in the polymerlayer 98, then through the metal trace or bus 831 a over the passivationlayer 831 a, then through an opening 534 in the passivation layer 5,then through the fine-line metal structure 634 under the passivationlayer 5, and to the input node (usually the gate of an MOS transistor inthe NOR gate 24) of the NOR gate 24; (2) in a second path, then downthrough an opening 532 in the passivation layer 5, then through thefine-line metal interconnection scheme 632 under the passivation layer5, and then to the input nodes (usually the gates of MOS transistors inthe NOR gate 24 and the NAND gate 23, respectively) of the NOR gate 22and the NAND gate 23.

Referring to 5B, 6B, 7B, 7C and 7D, the thick metal trace or bus 83, 831or 832 over the passivation layer 5 is be connected to an off-chip I/Ocircuit connected to an external circuit, and thereby the thick metaltrace or bus 83, 831 or 832 has no significant voltage drop or signaldegradation.

Now refer to FIGS. 5C-5E showing internal buffer circuits applied to theinternal circuit 21. The internal circuit 21 shown in FIG. 5B, 6B, 7B,7C and 7D may be an internal inverter shown in FIG. 5C. In a firstapplication, the size of the n-channel MOS 2101 and p-channel MOS 2102can be designed in a size often employed in the internal circuits 22, 23and 24. The size of an MOS transistor is defined as a ratio of aphysical channel width thereof to a physical channel length thereof. Then-channel MOS transistor 2101 may have a ratio of a physical channelwidth thereof to a physical channel length thereof ranging from 0.1 to20, ranging from 0.1 to 10, or preferably ranging from 0.2 to 2. Thep-channel MOS transistor 2102 may have a ratio of a physical channelwidth thereof to a physical channel length thereof ranging from 0.2 to40, ranging from 0.2 to 20, or preferably ranging from 0.4 to 4. In thefirst application, a current passing through the thick metal trace 83over the passivation layer 5 and outputting from the node Xo of theinternal circuit 21 may be in a range of between 50 μA and 2 mA, andpreferably of between 100 μA and 1 mA. In a second application, agreater drive current is required for the output of the inverter 211,for example, when a heavy load is demanded by the load internal circuits22, 23 and 24, or when the internal circuits 22, 23 and 24 are locatedfar away from the internal circuit 21, requiring interconnection metallines or traces connecting the internal circuit 21 and the internalcircuits 22, 23 and 24 in a distance of greater than 1 mm or of greaterthan 3 mm, for example. In the second application, the current outputfrom the inverter 211 is higher than that output from the regularinternal circuit, and is, for example, at 1 mA or 5 mA, or in a range ofbetween 500 μA and 10 mA, and preferably of between 700 μA and 2 mA.Hence, in the second application, the n-channel MOS transistor 2101 mayhave a ratio of a physical channel width thereof to a physical channellength thereof ranging from 1.5 to 30, and preferably ranging from 2.5to 10. The p-channel MOS transistor 2102 may have a ratio of a physicalchannel width thereof to a physical channel length thereof ranging from3 to 60, and preferably ranging from 5 to 20.

When the inverter 211 shown in FIG. 5C is applied to the internalcircuit 21 as shown in FIGS. 5B, 6B, 7B, 7C and 7D, the drains of then-channel MOS transistor 2101 and p-channel MOS transistor 2102, servingas the output node Xo of the internal circuit 21, are connected to thethick metal traces or buses 83, 831 or 832 over the passivation layer 5as shown in FIGS. 5B, 6B, 7B, 7C and 7D. The gates of the n-channel MOStransistor 2101 and p-channel MOS transistor 2102 serve as the inputnode Xi of the internal circuit 21.

Referring to FIG. 5C, the above-mentioned power plane, bus or trace 81,811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, over thepassivation layer 5 may connect the node P of the regulator or converter41 and the source of the p-channel MOS device 2102. The above-mentionedpower plane, bus or trace 81, 811 or 812 may contain a patterned circuitlayer over the patterned circuit layers 831 and/or 832 of the thick andwide signal trace, bus or plane 83 as shown in FIGS. 7B-7D.Alternatively, the thick and wide signal trace, bus or plane 83 as shownin FIGS. 7B-7D may contain a patterned circuit layer over that of theabove-mentioned power plane, bus or trace 81. The above-mentioned groundplane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C, over thepassivation layer 5 may connect the node Rs of the regulator orconverter 41 and the source of the n-channel MOS device 2101. Theabove-mentioned ground plane, bus or trace 82 or 821 may contain apatterned circuit layer over the patterned circuit layers 831 and/or 832of the thick and wide signal trace, bus or plane 83 as shown in FIGS.7B-7D. Alternatively, the thick and wide signal trace, bus or plane 83as shown in FIGS. 7B-7D may contain a patterned circuit layer over thatof the above-mentioned ground plane, bus or trace 82.

FIGS. 5D and 5E show an internal driver 212 and internal tri-stateoutput buffer 213, respectively. When the internal driver 212 shown inFIG. 5D is applied to the internal circuit 21 as shown in FIGS. 5B, 6B,7B, 7C and 7D, the drains of a n-channel MOS transistor 2103 andp-channel MOS transistor 2104, serving as the output node Xo of theinternal circuit 21, are connected to the thick metal traces or buses83, 831 or 832 over the passivation layer 5. The gates of a n-channelMOS transistor 2103′ and p-channel MOS transistor 2104′ serve as theinput node Xi of the internal circuit 21. The drains of the n-channelMOS transistor 2103′ and p-channel MOS transistor 2104′ are connected tothe gates of the n-channel MOS transistor 2103 and p-channel MOStransistor 2104.

When the internal tri-state output buffer 213 shown in FIG. 5E isapplied to the internal circuit 21 as shown in FIGS. 5B, 6B, 7B, 7C and7D, the drains of a n-channel MOS transistor 2107′ and p-channel MOStransistor 2108′ with a switch function controlled by an Enable signaltransmitted to the gate of the n-channel MOS transistor 2107′ andEnable(bar) signal transmitted to the gate of the p-channel MOStransistor 2108′, serving as the output node Xo of the internal circuit21, are connected to the thick metal traces or buses 83, 831 or 832 overthe passivation layer 5 as shown in FIGS. 5B, 6B, 7B, 7C and 7D. Thegates of a n-channel MOS transistor 2107 and p-channel MOS transistor2108 serve as the input node Xi of the internal circuit 21. The drainsof a n-channel MOS transistor 2107 and p-channel MOS transistor 2108 areconnected to the sources of the n-channel MOS transistor 2107′ andp-channel MOS transistor 2108′, respectively.

The internal driver 212 or internal tri-state output buffer 213, used todrive a signal through the post-passivation metal traces 83 and to theinternal circuits 22, 23 and 24, as shown in FIG. 5D or 5E, is similarto the off-chip driver or off-chip tri-state output buffer used to drivean external circuitry, to be discussed in the following FIG. 1A or 11D,respectively, except that (1) the output node Xo of the internal driver212 or internal tri-state output buffer 213 is not connected to anexternal circuit; (2) the greatest one of p-MOS transistors in theinternal driver 212 or internal tri-state output buffer 213 has a ratioof a physical channel width thereof to a physical channel length thereofsmaller than that of the greatest one of p-MOS transistors in theoff-chip driver or off-chip tri-state output buffer connected to anexternal circuit. The internal tri-state output buffer 213 providesdrive capability and switch capability, and is particularly useful totransmit a data signal or an address signal in a memory chip through thethick metal lines or traces 83 over the passivation layer 5 acting asdata or address buses.

In FIG. 5B, a relatively great drive current is required at the outputnode Xo of the internal circuit 21 when a heavy load is demanded by theinternal circuits 22, 23 and 24, or when the internal circuits 22, 23and 24 are far away from the internal circuit 21 in a distance ofgreater than 1 mm or of greater than 3 mm. To provide a relatively greatdrive current, the internal circuit 21 can be designed as an internaldriver 212 shown in FIG. 5D or an internal tri-state output buffer 213shown in FIG. 5E.

In FIGS. 5D and 5E, the n-channel MOS transistors 2103, 2107 and 2107′may have a ratio of a physical channel width thereof to a physicalchannel length thereof ranging from 1.5 to 30, and preferably rangingfrom 2.5 to 10. The p-channel MOS transistors 2104, 2108 and 2108′ mayhave a ratio of a physical channel width thereof to a physical channellength thereof ranging from 3 to 60, and preferably ranging from 5 to20. In FIG. 5D, the n-channel MOS transistor 2103′ may have a ratio of aphysical channel width thereof to a physical channel length thereofranging from 0.1 to 20, ranging from 0.1 to 10, or preferably rangingfrom 0.2 to 2, and the p-channel MOS transistor 2104′ may have a ratioof a physical channel width thereof to a physical channel length thereofranging from 0.2 to 40, ranging from 0.2 to 20, or preferably rangingfrom 0.4 to 4. Referring to FIGS. 5B, 5D and 5E, the internal driver 212or internal tri-state buffer 213 may drive a signal output from theoutput node Xo thereof through the thick metal trace or bus 83 over thepassivation layer 5 to the input nodes Ui, Vi and Wi of the internalcircuits 22, 23 and 24 but not to an external circuit. A current passingthrough the thick metal trace or line 83 over the passivation layer 5and outputting from the node Xo of the internal circuit 21, provided bythe internal driver 212 or internal tri-state buffer 213, may be between500 μA and 10 mA, and preferably between 700 μA and 2 mA.

Referring to FIG. 5D, the above-mentioned power plane, bus or trace 81,811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, over thepassivation layer 5 can connect the node P of the regulator or converter41 and the sources of the p-channel MOS devices 2104 and 2104′. Theabove-mentioned power plane, bus or trace 81, 811 or 812 may contain apatterned circuit layer over the patterned circuit layers 831 and/or 832of the thick and wide signal trace, bus or plane 83 as shown in FIGS.7B-7D. Alternatively, the thick and wide signal trace, bus or plane 83as shown in FIGS. 7B-7D may contain a patterned circuit layer over thatof the above-mentioned power plane, bus or trace 81. The above-mentionedground plane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C,over the passivation layer 5 can connect the node Rs of the regulator orconverter 41 and the sources of the n-channel MOS devices 2103 and2103′. The above-mentioned ground plane, bus or trace 82 or 821 maycontain a patterned circuit layer over the patterned circuit layers 831and/or 832 of the thick and wide signal trace, bus or plane 83 as shownin FIGS. 7B-7D. Alternatively, the thick and wide signal trace, bus orplane 83 as shown in FIGS. 7B-7D may contain a patterned circuit layerover that of the above-mentioned ground plane, bus or trace 82.

Referring to FIG. 5E, the above-mentioned power plane, bus or trace 81,811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, over thepassivation layer 5 can connect the node P of the regulator or converter41 and the source of the p-channel MOS device 2108. The above-mentionedpower plane, bus or trace 81, 811 or 812 may contain a patterned circuitlayer over the patterned circuit layers 831 and/or 832 of the thick andwide signal trace, bus or plane 83 as shown in FIGS. 7B-7D.Alternatively, the thick and wide signal trace, bus or plane 83 as shownin FIGS. 7B-7D may contain a patterned circuit layer over that of theabove-mentioned power plane, bus or trace 81. The above-mentioned groundplane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C, over thepassivation layer 5 can connect the node Rs of the regulator orconverter 41 and the source of the n-channel MOS device 2107. Theabove-mentioned ground plane, bus or trace 82 or 821 may contain apatterned circuit layer over the patterned circuit layers 831 and/or 832of the thick and wide signal trace, bus or plane 83 as shown in FIGS.7B-7D. Alternatively, the thick and wide signal trace, bus or plane 83as shown in FIGS. 7B-7D may contain a patterned circuit layer over thatof the above-mentioned ground plane, bus or trace 82.

Alternatively, when a NMOS transistor in the internal circuit 21 havinga drain as the output node Xo of the internal circuit 21 has a ratio ofa physical channel width to a physical channel length ranging from 1.5to 30, and preferably ranging from 2.5 to 10, a NMOS transistor in theinternal circuit 22, 23 or 24 having a gate as the input node Ui, Vi andWi of the internal circuit 22, 23 or 24 has a ratio of physical channelwidth to physical channel length ranging from 0.1 to 20, ranging from0.1 to 10, or preferably ranging from 0.2 to 2. When a NMOS transistorin the internal circuit 21 having a drain as the output node Xo of theinternal circuit 21 has a ratio of a physical channel width to aphysical channel length ranging from 1.5 to 30, and preferably rangingfrom 2.5 to 10, a PMOS transistor in the internal circuit 22, 23 or 24having a gate as the input node Ui, Vi and Wi of the internal circuit22, 23 or 24 has a ratio of a physical channel width to a physicalchannel length ranging from 0.2 to 40, ranging from 0.2 to 20, orpreferably ranging from 0.4 to 4. When a PMOS transistor in the internalcircuit 21 having a drain as the output node Xo of the internal circuit21 has a ratio of a physical channel width to a physical channel lengthranging from 3 to 60, and preferably ranging from 5 to 20, a NMOStransistor in the internal circuit 22, 23 or 24 having a gate as theinput node Ui, Vi and Wi of the internal circuit 22, 23 or 24 has aratio of a physical channel width to a physical channel length rangingfrom 0.1 to 20, ranging from 0.1 to 10, or preferably ranging from 0.2to 2. When a PMOS transistor in the internal circuit 21 having a drainas the output node Xo of the internal circuit 21 has a ratio of aphysical channel width to a physical channel length ranging from 3 to60, and preferably ranging from 5 to 20, a PMOS transistor in theinternal circuit 22, 23 or 24 having a gate as the input node Ui, Vi andWi of the internal circuit 22, 23 or 24 has a ratio of a physicalchannel width to a physical channel length ranging from 0.2 to 40,ranging from 0.2 to 20, or preferably ranging from 0.4 to 4. In theabove-mentioned case, a signal output from the output node Xo of theinternal circuit 21 may pass through the thick metal plane, bus, traceor line 83 to the internal circuits 22, 23 and 24, with a current,passing through the thick metal plane, bus, trace or line 83, rangingfrom 500 microamperes to 10 milliamperes, and preferably ranging from700 microamperes to 2 milliamperes.

The concept shown in FIG. 5B can be applied to a memory chip, asillustrated in FIGS. 5F-5J.

Referring to FIG. 5F, the above-mentioned tri-state output buffer 213 isemployed to be the internal circuit 21 shown in FIGS. 5B, 6B, 7B, 7C and7D and has an input node Xi connected to an output node of an amplifier214 and an output node Xo connected to the internal circuits 22, 23 and24, such as logic gates, through the above mentioned thick metal plane,bus or trace 83, 831 or 832 over the passivation layer 5, as shown inFIGS. 5B, 6B, 7B, 7C and 7D, wherein the internal circuits 22, 23 and 24may alternatively be NOR gate, NAND gate, AND gate, OR gate, operationalamplifier, adder, multiplexer, diplexer, multiplier, A/D converter, D/Aconverter, CMOS transistor, bipolar CMOS transistor or bipolar circuit.The semiconductor chip may include a memory array comprising multiplememory cells connected to word lines, bit lines and bit (bar) lines.Each pair of bit line, such as 2171, and bit (bar) line, such as 2172,is connected to one of the amplifiers, such as 214, through the channelof the n-channel MOS transistors 2123 and 2122 controlled by CSI node.When the n-channel MOS transistors 2122 and 2123 are turned off in aninactive cycle, the noise on the bit line 2171 or on the bit (bar) line2172 can not be transmitted to the sense amplifier 214 nor has anegative impact on the sense amplifier 214.

In this case, the memory cell 215 is a static random access memory(SRAM) cell. Alternatively, the memory cell 215 may be a dynamic randomaccess memory (DRAM) cell, an erasable programmable read only memory(EPROM) cell, an electronic erasable programmable read only memory(EEPROM) cell, a flash memory cell, a read only memory (ROM) cell, or amagnetic random access memory (MRAM) cell, which is connected to one ormore logic gates 22, 23 and 24 through a thick metal traces 83, 831 or832 over the passivation layer 5, as shown in FIGS. 5B, 6B, 7B, 7C and7D. A sense amplifier 214, tri-state buffer 213, pass gate 216, latchmemory 217 or internal driver 212, as shown in FIGS. 5F-5J, may beoptionally set on the path between any kind of the exampled memory cell215 and the thick metal traces 83, 831 or 832 over the passivation layer5.

In case of SDRAM cell acting as the memory cell 215, a plurality of thememory cell 215 may be arranged in an array. A plurality of bit line2171 and bit (bar) line 2172 arranged in parallel are connected to thesources or drains of NMOS transistors 2120 and 2119 of the memory cells215 arranged in a column, respectively. A plurality of word linearranged in parallel and in vertical to the bit line 2171 and bit (bar)line 2172 is connected to the gate of NMOS transistors 2120 and 2119 ofthe memory cells 215 arranged in a row. The memory cell 215 furthercomprises two PMOS transistors 2116 and 2118 and two NMOS transistors2115 and 2117, wherein the gates of the PMOS transistor 2116 and theNMOS transistor 2115 and the drains of the PMOS transistor 2118 and theNMOS transistor 2117 are connected to the bit line 2171 through thechannel of the NMOS transistor 2120, and wherein the gates of the PMOStransistor 2118 and the NMOS transistor 2117 and the drains of the PMOStransistor 2116 and the NMOS transistor 2115 are connected to the bit(bar) line 2172 through the channel of the NMOS transistor 2119.

The sense amplifier 214, such as differential amplifier, can be coupledto multiple memory cells 215 arranged in a column through the bit line2171 and the bit (bar) line 2172. The sense amplifier 214 comprises twoPMOS transistors 2112 and 2114 and two NMOS transistors 2111 and 2113,wherein the gates of the PMOS transistors 2112 and 2114 are connected tothe drains of the NMOS transistor 2111 and the PMOS transistor 2112, andwherein the drains of the PMOS transistor 2114 and the NMOS transistor2113 serving as an output node of the sense amplifier 214 are connectedto the gates of the PMOS transistor 2108 and the NMOS transistor 2107 inthe above-mentioned tri-state buffer 213. The gate of the NMOStransistor 2113 is connected to the bit line 2171. The gate of the NMOStransistor 2111 is connected to the bit (bar) line 2172. The descriptionand specification of the tri-state buffer 213 may be referred to theabove illustration shown in FIG. 5E.

Referring to FIG. 5F, the node P of the regulator or converter 41 can beconnected to the sources of the PMOS transistors 2116 and 2118 of thememory cell 215, the sources of the PMOS transistors 2112 and 2114 ofthe sense amplifier 214 and the source of the PMOS transistor 2108 ofthe tri-state output buffer 213 through the above-mentioned power plane,bus or trace 81, 811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3Cand 3D, over the passivation layer 5. The above-mentioned power plane,bus or trace 81, 811 or 812 may contain a patterned circuit layer overthe patterned circuit layers 831 and/or 832 of the thick and wide signaltrace, bus or plane 83 as shown in FIGS. 7B-7D. Alternatively, the thickand wide signal trace, bus or plane 83 as shown in FIGS. 7B-7D maycontain a patterned circuit layer over that of the above-mentioned powerplane, bus or trace 81. The node Rs of the regulator or converter 41 canbe connected to the sources of the NMOS transistors 2115 and 2117 of thememory cell 215, the sources of the NMOS transistors 2111 and 2113 ofthe sense amplifier 214 and the source of the NMOS transistor 2107 ofthe tri-state output buffer 213 through the above-mentioned groundplane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C, over thepassivation layer 5. The differential sense amplifier 214 is isolatedfrom Vss by a transistor 2121, and controlled by a column selectionsignal (CS2) to save power consumption. The transistor 2121 is turnedoff when the memory cell 215 is not read. The above-mentioned groundplane, bus or trace 82 or 821 may contain a patterned circuit layer overthe patterned circuit layers 831 and/or 832 of the thick and wide signaltrace, bus or plane 83 as shown in FIGS. 7B-7D. Alternatively, the thickand wide signal trace, bus or plane 83 as shown in FIGS. 7B-7D maycontain a patterned circuit layer over that of the above-mentionedground plane, bus or trace 82.

When the memory cell 215 is in a “READ” operation with the NMOStransistors 2120 and 2119 being turned on, the state latched in thememory cell 215, such as bit data and bit (bar) data, may be output tothe bit line 2171 and bit (bar) line 2172 through the channels of theNMOS transistors 2120 and 2119, respectively. The bit data and bit (bar)data may be transmitted to the sense amplifier 214 through the bit line2171 and bit (bar) line 2172, respectively, to initially amplify the bitdata and the bit (bar) data, leading the bit data and the bit (bar) datato have a desirable waveform or voltage level. The initially amplifiedbit data or bit (bar) data output from the amplifier 214 may betransmitted to a tri-state output buffer 213 to further amplify theinitially amplified bit data or bit (bar) data, but FIG. 5F only showthe initially amplified bit (bar) data output from the amplifier 214 istransmitted to the input node Xi of the tri-state output buffer 213.Further amplified bit (bar) data or bit data output from a tri-statebuffer can be transmitted to the internal circuits 22, 23 and 24 throughthe thick metal planes or buses 83, 831 or 832, as shown in FIGS. 5B,6B, 7B, 7C and 7D, but FIG. 5F only show the further amplified bit datais output from the tri-state output buffer 213.

The bit line 2171 and bit (bar) line 2172 may be provided by fine-linemetal layers, made of sputtered aluminum or damascene copper, only underthe passivation layer 5. Alternatively, the bit line 2171 and bit (bar)line 2172 may be provided by the interconnecting structure over thepassivation layer 5 and under the passivation layer 5, wherein theportion under the passivation layer 5 may comprise sputtered aluminumlayer or damascene copper layer having a thickness of between 0.01 and 2microns, and the portion over the passivation layer 5 may compriseelectroplated copper or electroplated gold having a thickness of between2 and 20 microns.

In this case, the thick metal buses or traces 83, 831 or 832 shown inFIGS. 5B, 6B, 7B, 7C and 7D may be called as bit buses to transmitfurther amplified bit data or bit (bar) data with 4 bits width, 8 bitswidth, 16 bits width, 32 bits width, 64 bits width, 128 bits width, 256bits width, 512 bits width, 1024 bits width, 2048 bits width or 4096bits width, output from the tri-state buffers 213. Accordingly, 4, 8,16, 32, 64, 128, 256, 512, 1024, 2048 or 4098 bit buses arranged inparallel and over the passivation layer 5, may connect the output nodesXo of multiple internal circuits 21, the tri-state buffers 213 in thiscase, to multiple internal circuits 22, 23 and 24, such as NOR gates,NAND gates, AND gates, OR gates, operational amplifiers, adders,multiplexers, diplexers, multipliers, A/D converters, D/A converters,CMOS transistors, bipolar CMOS transistors or bipolar circuits.

Alternatively, multiple address buses 85 connecting an address decoder205 and the outputs of multiple internal circuits 25 and 26 can beformed over the passivation layer 5, as shown in FIG. 5U, to transmit anaddress data from one of the internal circuits 25 and 26 to the addressdecoder 205 during a “READ” operation, wherein the internal circuits 25and 26 may be NOR gate, NAND gate, AND gate, OR gate, operationalamplifier, adder, multiplexer, diplexer, multiplier, A/D converter, D/Aconverter, CMOS transistor, bipolar CMOS transistor or bipolar circuit.The address decoder 205 is connected to multiple word lines coupled withmultiple memory cells in a memory array. Referring to FIGS. 5F and 5U,one of the word lines 2175 is connected to the gates of the NMOStransistors 2120 and 2119 of the memory cell 115, transmitting a signalfrom the address decoder 205 to the memory cell to control whether thelogic level of bit data saved in the trace connecting the drains of thePMOS transistor 2118 and NMOS transistor 2117 and the gates of the PMOStransistor 2116 and NMOS transistor 2115 and the logic level of bit(bar) data saved in the trace connecting the drains of the PMOStransistor 2116 and NMOS transistor 2115 and the gates of the PMOStransistor 2118 and NMOS transistor 2117 are transmitted to the bit line2171 and the bit (bar) line 2172 through the channels of the NMOStransistors 2120 and 2119, respectively. The sense amplifier 214receives the bit data and bit (bar) data and initially amplifies the bit(bar) data. The initially amplified the bit (bar) data output from thesense amplifier 214 may be transmitted to the gates of the PMOStransistor 2108 and NMOS transistor 2107 of the tri-state buffer 213through the trace 2179 under the passivation layer 5. Two traces 2177and 2178 connect the address decoder 205 and the tri-state buffer 213,transmitting an ENABLE signal and an ENABLE (bar) signal from theaddress decoder 205 to the tri-state buffer 213 to control whether theabove-mentioned further amplified bit signal is output from thetri-state buffer 213 to the data bus 83 over the passivation layer 5.

Other embodiments as described below can be alternatively attained. Samereference numbers in this patent application indicate same or similarelements.

Referring to FIGS. 5B, 6B, 7B, 7C and 7D, the internal circuit 21 may bea pass gate 216 as shown in FIG. 5G. The pass gate 216 may comprise anNMOS transistor 2124 having a gate connected to an address decoder 205through a trace 2180 under the passivation layer 5, as shown in FIG. 5V.In a “READ” operation, the address decoder 205 receives an address datathrough multiple address buses 85 over the passivation layer 5. Theaddress decoder 205 output a READ ENABLE data to the gate of the NMOStransistor 2124 through the trace 2180 to control whether the NMOStransistor 2124 is turned on or off. When the NMOS transistor 2124 ofthe pass gate 216 is turned on, the initially amplified bit (bar) dataoutput from the sense amplifier 214 can be transmitted to the data bus83, 831 or 832 over the passivation layer 5 through the channel of theNMOS transistor 2124.

Referring to FIGS. 5B, 6B, 7B, 7C and 7D, the internal circuit 21 may bea latch circuit 217 as shown in FIG. 5H. The latch circuit 217 maytemporally store the data output from the sense amplifier 214. The latchcircuit 217 comprises two PMOS transistors 2901 and 2902 and two NMOStransistors 2903 and 2904. A trace 2905 connects the gates of the PMOStransistor 2902 and NMOS transistor 2904 and the drains of the PMOStransistor 2901 and NMOS transistor 2903. A trace 2906 connects thegates of the PMOS transistor 2901 and NMOS transistor 2903 and thedrains of the PMOS transistor 2902 and NMOS transistor 2904. The latchcircuit 217 may further comprise two NMOS transistors 2129 and 2130having the gates connected to an address decoder 205 through metaltraces 2181 and 2182 under the passivation layer 5, as shown in FIG. 5W.In a “READ” operation, the address decoder 205 receives an address datathrough multiple address buses 85 over the passivation layer 5. Theaddress decoder 205 output READ ENABLE data (RE1 and RE2) to the gatesof the NMOS transistors 2129 and 2130 through the traces 2181 and 2182to control whether the NMOS transistors 2129 and 2130 are turned on oroff, respectively. When the NMOS transistor 2129 is turned on, theinitially amplified bit (bar) data output from the sense amplifier 214can be transmitted to the trace 2905 through the channel of the NMOStransistor 2129. The trace 2905 latches the bit (bar) data and the trace2906 latches the bit data. When the NMOS transistor 2130 is turned on,the bit data output from the trace 2906 of the latch circuit 217 can betransmitted to the data bus 83, 831 or 832 through the channel of theNMOS transistor 2130.

Referring to FIG. 5H, the node P of the regulator or converter 41 can beconnected to the sources of the PMOS transistors 2116 and 2118 of thememory cell 215, the sources of the PMOS transistors 2112 and 2114 ofthe sense amplifier 214 and the sources of the PMOS transistors 2901 and2902 of the latch circuit 217 through the above-mentioned power plane,bus or trace 81, 811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3Cand 3D, over the passivation layer 5. The above-mentioned power plane,bus or trace 81, 811 or 812 may contain a patterned circuit layer overthe patterned circuit layers 831 and/or 832 of the thick and wide signaltrace, bus or plane 83 as shown in FIGS. 7B-7D. Alternatively, the thickand wide signal trace, bus or plane 83 as shown in FIGS. 7B-7D maycontain a patterned circuit layer over that of the above-mentioned powerplane, bus or trace 81. The node Rs of the regulator or converter 41 canbe connected to the sources of the NMOS transistors 2115 and 2117 of thememory cell 215, the sources of the NMOS transistors 2111 and 2113 ofthe sense amplifier 214 and the sources of the NMOS transistors 2903 and2904 of the latch circuit 217 through the above-mentioned ground plane,bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C, over thepassivation layer 5. The above-mentioned ground plane, bus or trace 82or 821 may contain a patterned circuit layer over the patterned circuitlayers 831 and/or 832 of the thick and wide signal trace, bus or plane83 as shown in FIGS. 7B-7D. Alternatively, the thick and wide signaltrace, bus or plane 83 as shown in FIGS. 7B-7D may contain a patternedcircuit layer over that of the above-mentioned ground plane, bus ortrace 82.

However, the pass gate 216 in FIG. 5G or the latch circuit 217 in FIG.5H does not provide great drive capability. To drive heavy load of thelogic circuits 22, 23 and 24, or to transmit bit (bar) data output fromthe pass circuit 216 or bit data output from the latch circuit 217 tothe logic circuits 22, 23 and 24 in a long distance, the internalcircuit 21 may comprise the above-mentioned internal driver 212connected to the output node of the pass gate 216, as shown in FIG. 51,or connected to the output node of the latch circuit 217, as shown inFIG. 5J, to amplify bit (bar) data output from the pass gate 216 or bitdata output from the latch circuit 217. Referring to FIG. 51, theamplified bit (bar) data output from the internal driver 212 may betransmitted to the internal circuits 22, 23 and 24 through the data bus83, 831 or 832 over the passivation layer 5, as shown in FIGS. 5B, 6B,7B, 7C and 7D. Referring to FIG.5J, the amplified bit data output fromthe internal driver 212 may be transmitted to the internal circuits 22,23 and 24 through the data bus 83, 831 or 832 over the passivation layer5, as shown in FIGS. 5B, 6B, 7B, 7C and 7D.

Referring to FIG. 5I, the node P of the regulator or converter 41 can beconnected to the sources of the PMOS transistors 2116 and 2118 of thememory cell 215, the sources of the PMOS transistors 2112 and 2114 ofthe sense amplifier 214 and the sources of the PMOS transistors 2104′and 2104 of the internal driver 212 through the above-mentioned powerplane, bus or trace 81, 811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C,3B, 3C and 3D, over the passivation layer 5. The above-mentioned powerplane, bus or trace 81, 811 or 812 may contain a patterned circuit layerover the patterned circuit layers 831 and/or 832 of the thick and widesignal trace, bus or plane 83 as shown in FIGS. 7B-7D. Alternatively,the thick and wide signal trace, bus or plane 83 as shown in FIGS. 7B-7Dmay contain a patterned circuit layer over that of the above-mentionedpower plane, bus or trace 81. The node Rs of the regulator or converter41 can be connected to the sources of the NMOS transistors 2115 and 2117of the memory cell 215, the sources of the NMOS transistors 2111 and2113 of the sense amplifier 214 and the sources of the NMOS transistors2103′ and 2103 of the driver circuit 212 through the above-mentionedground plane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C,over the passivation layer 5. The above-mentioned ground plane, bus ortrace 82 or 821 may contain a patterned circuit layer over the patternedcircuit layers 831 and/or 832 of the thick and wide signal trace, bus orplane 83 as shown in FIGS. 7B-7D. Alternatively, the thick and widesignal trace, bus or plane 83 as shown in FIGS. 7B-7D may contain apatterned circuit layer over that of the above-mentioned ground plane,bus or trace 82.

Referring to FIG. 5J, the node P of the regulator or converter 41 can beconnected to the sources of the PMOS transistors 2116 and 2118 of thememory cell 215, the sources of the PMOS transistors 2112 and 2114 ofthe sense amplifier 214, the sources of the PMOS transistors 2901 and2902 of the latch circuit 217 and the sources of the PMOS transistors2104′ and 2104 of the internal driver 212 through the above-mentionedpower plane, bus or trace 81, 811 or 812, as shown in FIGS. 1B, 1C, 2B,2C, 3B, 3C and 3D, over the passivation layer 5. The above-mentionedpower plane, bus or trace 81, 811 or 812 may contain a patterned circuitlayer over the patterned circuit layers 831 and/or 832 of the thick andwide signal trace, bus or plane 83 as shown in FIGS. 7B-7D.Alternatively, the thick and wide signal trace, bus or plane 83 as shownin FIGS. 7B-7D may contain a patterned circuit layer over that of theabove-mentioned power plane, bus or trace 81. The node Rs of theregulator or converter 41 can be connected to the sources of the NMOStransistors 2115 and 2117 of the memory cell 215, the sources of theNMOS transistors 2111 and 2113 of the sense amplifier 214, the sourcesof the NMOS transistors 2903 and 2904 of the latch circuit 217 and thesources of the NMOS transistors 2103′ and 2103 of the internal driver212 through the above-mentioned ground plane, bus or trace 82 or 821, asshown in FIGS. 1C, 2C and 3C, over the passivation layer 5. Theabove-mentioned ground plane, bus or trace 82 or 821 may contain apatterned circuit layer over the patterned circuit layers 831 and/or 832of the thick and wide signal trace, bus or plane 83 as shown in FIGS.7B-7D. Alternatively, the thick and wide signal trace, bus or plane 83as shown in FIGS. 7B-7D may contain a patterned circuit layer over thatof the above-mentioned ground plane, bus or trace 82.

Alternatively, referring to FIG. 5K, the output node Wo of the internalcircuit 24 is connected to the input nodes Xi, Ui and Vi of the internalcircuits 21, 22 and 23 through the thick metal plane, bus, trace or line83′ over the passivation layer 5. The internal circuit 24, such as NORgate, may send a signal or data from the output node Wo thereof to theinput node Xi′ of the internal circuit 21, such as a receiver 212′ shownin FIG. 5L, a tri-state input buffer 213′ shown in FIG. 5M or otherinternal circuits, through a fine-line metal structure 634′ under thepassivation layer 5, then through an opening 534′ in the passivationlayer 5, then through the thick metal plane, line or trace 83′ over thepassivation layer 5, then through another opening 531 ′ in thepassivation layer 5, and then through a fine-line metal structure 631 ′under the passivation layer 5. Besides, a signal or data output from theoutput node Wo of the internal circuit 24 may be also transmitted to theinput node Ui of the internal circuit 22, such as NOR gate, through thefine-line metal structure 634′ under the passivation layer 5, thenthrough the opening 534′ in the passivation layer 5, then through thethick metal plane, line or trace 83′ over the passivation layer 5, thenthrough another opening 532′ in the passivation layer 5, then throughthe fine-line metal structures 632 a′ and 632 b 40 under the passivationlayer 5. Besides, a signal or data output from the output node Wo of theNOR gate 24 may be also transmitted to the input node Vi of the internalcircuit 23, such as NAND gate, through the fine-line metal structure634′ under the passivation layer 5, then through the opening 534′ in thepassivation layer 5, then through the thick metal plane, line or trace83′ over the passivation layer 5, then through another opening 532′ inthe passivation layer 5, then through the fine-line metal structures 632a′ and 632 c′ under the passivation layer 5.

The fine-line metal structures 634′, 632′ and 631′ can be formed withstacked metal plugs, having a similar structure of the fine line metalstructures 634, 632 and 631, respectively, as shown in 7B, 7C and 7D.The internal circuits 21, 22 and 23 may receive a signal output from theoutput node Wo of the internal circuit 24 at the input node Xi′, Ui andVi thereof, and may output a signal from the output node Xo′, Uo and Vothereof to other internal circuits through metal traces under thepassivation layer 5.

The structure over the passivation layer 5 shown in FIGS. 7B-7D,providing the above-mentioned thick metal trace, line or plane 83, canalso be applied to forming the thick metal trace, line or plane 83′illustrated in FIG. 5K. All combinations for the polymer layers 99, 98and 95 and the circuit metal layers 831 and 832 illustrated in FIGS.7B-7D can be applied to the combinations for one or more polymer layersand one or more circuit metal layers over the passivation layer 5,illustrated in FIG. 5K.

In a case, the internal circuit 21 may be an internal receiver 212′ asshown in FIG. 5L, or an internal input tri-state buffer 213′ as shown inFIG. 5M. Referring to FIGS. 5K and 5L, the internal receiver 212′ mayreceive a signal passing through the thick metal trace or bus 83 overthe passivation layer 5 and then may output an amplified signal from theoutput node Xo′ thereof to other internal circuits but not to anexternal circuit through a metal trace under the passivation layer 5.Referring to FIGS. 5K and 5M, the internal input tri-state buffer 213′may receive a signal passing through the thick metal trace or bus 83over the passivation layer 5 and then may output an amplified signalfrom the output node Xo′ thereof to other internal circuits but not toan external circuit through a metal trace under the passivation layer 5.

The internal receiver 212′ in FIG. 5L has a similar circuit design tothe internal driver 212 in FIG. 5D. In FIGS. 5D and 5L, same referencenumbers indicate same elements with same characteristics. The internalinput tri-state buffer 213′ in FIG. 5M has a similar circuit design tothe internal output tri-state buffer 213 in FIG. 5E. In FIGS. 5E and 5M,same reference numbers indicate same elements with same characteristics.

The output node Xo′ of the internal receiver 212′ or internal tri-stateinput buffer 213′ is not connected to an external circuit but connectedto an internal circuit under the passivation layer 5. The internaltri-state input buffer 213′ provides amplifying capability and switchcapability, and is particularly useful to amplify a data signal or anaddress signal having passed through the thick metal lines or traces 83′over the passivation layer 5 acting as data or address buses.

In FIG. 5K, a relatively great output current is required at the outputnode Xo′ of the internal circuit 21 when a heavy load is demanded by aninternal circuit connected to the output node Xo′ of the internalcircuit 21, or when the internal circuit 24 is far away from theinternal circuit 21 in a distance of greater than 1 mm or of greaterthan 3 mm. To provide a relatively great output current, the internalcircuit 21 can be designed as an internal receiver 212′ shown in FIG. 5Lor an internal tri-state input buffer 213′ shown in FIG. 5M.

Referring to FIG. 5K, a signal output from the internal circuit 24 canbe transmitted to an n-channel MOS transistor of the internal circuit21, wherein the n-channel MOS transistor may have a ratio of a physicalchannel width thereof to a physical channel length thereof ranging from0.1 to 20, ranging from 0.1 to 10, or preferably ranging from 0.2 to 2.Alternatively, a signal output from the internal circuit 24 can betransmitted to a p-channel MOS transistor of the internal circuit 21,wherein the p-channel MOS transistor 2102 may have a ratio of a physicalchannel width thereof to a physical channel length thereof ranging from0.2 to 40, ranging from 0.2 to 20, or preferably ranging from 0.4 to 4.In this application, the current level output from the internal circuit24 and transmitted through the thick metal trace 83′ over thepassivation layer 5 is, for example, in a range of between 50 μA and 2mA, and preferably of between 100 μA and 1 mA.

In FIGS. 5L and 5M, the n-channel MOS transistors 2103, 2107 and 2107′may have a ratio of a physical channel width thereof to a physicalchannel length thereof ranging from 1.5 to 30, and preferably rangingfrom 2.5 to 10. The p-channel MOS transistors 2104, 2108 and 2108′ mayhave a ratio of a physical channel width thereof to a physical channellength thereof ranging from 3 to 60, and preferably ranging from 5 to20. In FIG. 5L, the n-channel MOS transistor 2103′ may have a ratio of aphysical channel width thereof to a physical channel length thereofranging from 0.1 to 20, ranging from 0.1 to 10, or preferably rangingfrom 0.2 to 2, and the p-channel MOS transistor 2104′ may have a ratioof a physical channel width thereof to a physical channel length thereofranging from 0.2 to 40, ranging from 0.2 to 20, or preferably rangingfrom 0.4 to 4. Referring to FIGS. 5K, 5L and 5M, the internal receiver212 or internal tri-state input buffer 213 may receive a signal outputfrom the output node Wo of the internal circuit 24 and transmittedthrough the thick metal trace or bus 83′ over the passivation layer 5but not to an external circuit. A current passing through the thickmetal trace or line 83′ over the passivation layer 5 and inputting thenode Xi′ of the internal circuit 21, provided by the internal driver 212or internal tri-state buffer 213, may be between 500 μA and 10 mA, andpreferably between 700 μA and 2 mA.

The concept shown in FIG. 5K can be applied to a memory chip, asillustrated in FIGS. 5N-5R. The memory chip includes memory cells 215and sense amplifiers 214 that can be referred to those illustrated inFIG. 5F. In FIGS. 5F and 5N-5R, same reference numbers indicate sameelements.

Referring to FIG. 5N, the above-mentioned tri-state input buffer 213′ isemployed to be the internal circuit 21 shown in FIGS. 5K and has anoutput node Xo′ connected to the bit (bar) line 2172 and an input nodeXi′ connected to the internal circuits 22, 23 and 24, such as logicgates, through the above mentioned thick metal plane, bus or trace 83′over the passivation layer 5, wherein the internal circuit 24 mayalternatively be NOR gate, NAND gate, AND gate, OR gate, operationalamplifier, adder, multiplexer, diplexer, multiplier, A/D converter, D/Aconverter, CMOS transistor, bipolar CMOS transistor or bipolar circuit.

In this case, the memory cell 215 is a static random access memory(SRAM) cell. Alternatively, the memory cell 215 may be a dynamic randomaccess memory (DRAM) cell, an erasable programmable read only memory(EPROM) cell, an electronic erasable programmable read only memory(EEPROM) cell, a flash memory cell, a read only memory (ROM) cell, or amagnetic random access memory (MRAM) cell, which is connected to theoutput node Wo of the logic gate 24 through a thick metal traces 83′over the passivation layer 5. A tri-state input buffer 213′, pass gate216′, latch memory 217′ or internal receiver 212′, as shown in FIGS.5N-5R, may be optionally set on the path between any kind of theexampled memory cell 215 and the thick metal traces 83′ over thepassivation layer 5.

Referring to FIG. 5N, the node P of the regulator or converter 41 can beconnected to the sources of the PMOS transistors 2116 and 2118 of thememory cell 215, the sources of the PMOS transistors 2112 and 2114 ofthe sense amplifier 214 and the source of the PMOS transistor 2108 ofthe tri-state input buffer 213′ through the above-mentioned power plane,bus or trace 81, 811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3Cand 3D, over the passivation layer 5. The above-mentioned power plane,bus or trace 81, 811 or 812 may contain a patterned circuit layer overthe patterned circuit layers 831 and/or 832 of the thick and wide signaltrace, bus or plane 83 as shown in FIGS. 7B-7D. Alternatively, the thickand wide signal trace, bus or plane 83 as shown in FIGS. 7B-7D maycontain a patterned circuit layer over that of the above-mentioned powerplane, bus or trace 81. The node Rs of the regulator or converter 41 canbe connected to the sources of the NMOS transistors 2115 and 2117 of thememory cell 215, the sources of the NMOS transistors 2111 and 2113 ofthe sense amplifier 214 and the source of the NMOS transistor 2107 ofthe tri-state input buffer 213′ through the above-mentioned groundplane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C, over thepassivation layer 5. The above-mentioned ground plane, bus or trace 82or 821 may contain a patterned circuit layer over the patterned circuitlayers 831 and/or 832 of the thick and wide signal trace, bus or plane83 as shown in FIGS. 7B-7D. Alternatively, the thick and wide signaltrace, bus or plane 83 as shown in FIGS. 7B-7D may contain a patternedcircuit layer over that of the above-mentioned ground plane, bus ortrace 82.

Referring to FIG. 5N, when the memory cell 215 is in a “WRITE”operation, a bit signal can be transmitted to the input node Xi′ of thetri-state input buffer 213′, that is, the gates of the PMOS transistors2108 and the NMOS transistor 2107, through the thick metal line, traceor plane 83′ over the passivation layer 5, from the output node Wo ofthe internal circuit 24. An amplified bit (bar) signal having adesirable waveform or voltage level can be output from the output nodeXo′ of the tri-state input buffer 213′, that is, the source of the PMOStransistor 2108′ or the source of the NMOS transistor 2107′, to the bit(bar) line 2172. With the NMOS transistors 2122 and 2119 being turnedon, the bit (bar) signal on the bit (bar) line can be saved on the traceconnecting the gates of the PMOS transistor 2118 and NMOS transistor2117 and the sources of the PMOS transistor 2116 and NMOS transistor2115, and the bit signal can be saved on the trace connecting the gatesof the PMOS transistor 2116 and NMOS transistor 2115 and the sources ofthe PMOS transistor 2118 and NMOS transistor 2117.

In this case, the thick metal buses or traces 83′ may be called as bitbuses to transmit to-be-written bit data or bit (bar) data with 4 bitswidth, 8 bits width, 16 bits width, 32 bits width, 64 bits width, 128bits width, 256 bits width, 512 bits width, 1024 bits width, 2048 bitswidth or 4096 bits width, output from the tri-state buffers 213.Accordingly, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048 or 4098 bitbuses arranged in parallel and over the passivation layer 5, may connectthe input nodes Xi′ of multiple internal circuits 21, the tri-stateinput buffers 213′ in this case, to multiple output nodes of multipleinternal circuits 24, such as NOR gates, NAND gates, AND gates, ORgates, operational amplifiers, adders, multiplexers, diplexers,multipliers, A/D converters, D/A converters, CMOS transistors, bipolarCMOS transistors or bipolar circuits.

Alternatively, multiple address buses 85 connecting an address decoder205 and the outputs of multiple internal circuits 25 and 26 can beformed over the passivation layer 5, as shown in FIG. 5X, to transmit anaddress data from one of the internal circuits 25 and 26 to the addressdecoder 205 during a “WRITE” operation, wherein the internal circuits 25and 26 may be NOR gate, NAND gate, AND gate, OR gate, operationalamplifier, adder, multiplexer, diplexer, multiplier, A/D converter, D/Aconverter, CMOS transistor, bipolar CMOS transistor or bipolar circuit.The address decoder 205 is connected to multiple word lines coupled withmultiple memory cells in a memory array. Referring to FIGS. 5N and 5X,one of the word lines 2175 is connected to the gates of the NMOStransistors 2120 and 2119 of the memory cell 115, transmitting a signalfrom the address decoder 205 to the memory cell to control whether thelogic level of bit data on the bit line 2171 is saved in the traceconnecting the drains of the PMOS transistor 2118 and NMOS transistor2117 and the gates of the PMOS transistor 2116 and NMOS transistor 2115through the channel of the NMOS transistor 2120 and whether the logiclevel of bit (bar) data on the bit (bar) line 2172 is saved in the traceconnecting the drains of the PMOS transistor 2116 and NMOS transistor2115 and the gates of the PMOS transistor 2118 and NMOS transistor 2117are transmitted to the bit line 2171 and the bit (bar) line 2172 throughthe channel of the NMOS transistor 2119. Two traces 2177′ and 2178′connect the address decoder 205 and the tri-state input buffer 213′,transmitting an ENABLE signal and an ENABLE (bar) signal from theaddress decoder 205 to the tri-state input buffer 213′ to controlwhether the amplified bit (bar) signal is output from the tri-stateinput buffer 213′ to the bit (bar) line 2172.

Other embodiments as described below can be alternatively attained. Samereference numbers in this patent application indicate same or similarelements.

Referring to FIGS. 5K, the internal circuit 21 may be a pass gate 216′as shown in FIG. 50. The pass gate 216′ may comprise an NMOS transistor2124′ having a gate connected to an address decoder 205 through a trace2180′ under the passivation layer 5, as shown in FIG. 5Y. In a “WRITE”operation, the address decoder 205 receives an address data throughmultiple address buses 85 over the passivation layer 5. The addressdecoder 205 output a WRITE ENABLE data to the gate of the NMOStransistor 2124′ through the trace 2180′ to control whether the NMOStransistor 2124′ is turned on or off. When the NMOS transistor 2124′ ofthe pass gate 216′ is turned on, the bit data transmitted through thethick metal line, trace or plane 83′ can be output from the pass gate216′ to the bit line 2171 through the channel of the NMOS transistor2124′.

Referring to FIGS. 5K, the internal circuit 21 may be a latch circuit217′ as shown in FIG. 5P. The latch circuit 217′ may temporally storethe data transmitted through the thick metal line, trace or plane 83′.The latch circuit 217′ comprises two PMOS transistors 2901′ and 2902′and two NMOS transistors 2903′ and 2904′. A trace 2905′ connects thegates of the PMOS transistor 2902′ and NMOS transistor 2904′ and thedrains of the PMOS transistor 2901′ and NMOS transistor 2903′. A trace2906′ connects the gates of the PMOS transistor 2901′ and NMOStransistor 2903′ and the drains of the PMOS transistor 2902′ and NMOStransistor 2904′. The latch circuit 217′ may further comprise two NMOStransistors 2129′ and 2130′ having the gates connected to an addressdecoder 205 through metal traces 2181′ and 2182′ under the passivationlayer 5, as shown in FIG. 5Z. In a “WRITE” operation, the addressdecoder 205 receives an address data output from the output nodes Ao orBo of the internal circuit 25 or 26 through multiple address buses 85over the passivation layer 5. The address decoder 205 output WRITEENABLE data (WE1 and WE2) to the gates of the NMOS transistors 2129′ and2130′ through the traces 2181′ and 2182′ to control whether the NMOStransistors 2129′ and 2130′ are turned on or off, respectively. When theNMOS transistor 2130′ is turned on, the bit (bar) data output from theinternal circuit 24 through the thick metal line, trace or plane 83′,data bus, over the passivation layer 5 can be latched in the trace 2906′through the channel of NMOS transistor 2130′, and the bit data islatched in the trace 2905′. When the NMOS transistor 2129′ is turned on,the bit data latched in the trace 2905′ can be output to the bit line2171 through the channel of the NMOS transistor 2129′.

Referring to FIG. 5P, the node P of the regulator or converter 41 can beconnected to the sources of the PMOS transistors 2116 and 2118 of thememory cell 215, the sources of the PMOS transistors 2112 and 2114 ofthe sense amplifier 214 and the sources of the PMOS transistors 2901′and 2902′ of the latch circuit 217 through the above-mentioned powerplane, bus or trace 81, 811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C,3B, 3C and 3D, over the passivation layer 5. The above-mentioned powerplane, bus or trace 81, 811 or 812 may contain a patterned circuit layerover the patterned circuit layers 831 and/or 832 of the thick and widesignal trace, bus or plane 83 as shown in FIGS. 7B-7D. Alternatively,the thick and wide signal trace, bus or plane 83 as shown in FIGS. 7B-7Dmay contain a patterned circuit layer over that of the above-mentionedpower plane, bus or trace 81. The node Rs of the regulator or converter41 can be connected to the sources of the NMOS transistors 2115 and 2117of the memory cell 215, the sources of the NMOS transistors 2111 and2113 of the sense amplifier 214 and the sources of the NMOS transistors2903′ and 2904′ of the latch circuit 217 through the above-mentionedground plane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C,over the passivation layer 5. The above-mentioned ground plane, bus ortrace 82 or 821 may contain a patterned circuit layer over the patternedcircuit layers 831 and/or 832 of the thick and wide signal trace, bus orplane 83 as shown in FIGS. 7B-7D. Alternatively, the thick and widesignal trace, bus or plane 83 as shown in FIGS. 7B-7D may contain apatterned circuit layer over that of the above-mentioned ground plane,bus or trace 82.

However, the pass gate 216′ in FIG. 50 or the latch circuit 217′ in FIG.5P may not provide the enough sensitivity to detect a weak voltagevariation at the input node of the pass gate 216′ or the latch circuit217′ in a “WRITE” operation. To amplify the voltage level of a signaltransmitted through the thick metal line, trace or plane 83′ in a longdistance and output from the logic circuit 24, the internal circuit 21may comprise the above-mentioned internal receiver 212′ connected to theinput node of the pass gate 216′, as shown in FIG. 5Q, or connected tothe input node of the latch circuit 217′, as shown in FIG. 5R, toamplify bit data inputting to the pass gate 216′ or to the latch circuit217′. Referring to FIGS.5Q and 5R, the input node of the internalreceiver 212′ is connected to the output node Wo of the internal circuit24 through the thick metal line, trace or plane 83′ as shown in FIG. 5K.

Referring to FIG. 5Q, the node P of the regulator or converter 41 can beconnected to the sources of the PMOS transistors 2116 and 2118 of thememory cell 215, the sources of the PMOS transistors 2112 and 2114 ofthe sense amplifier 214 and the sources of the PMOS transistors 2104′and 2104 of the internal receiver 212′ through the above-mentioned powerplane, bus or trace 81, 811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C,3B, 3C and 3D, over the passivation layer 5. The above-mentioned powerplane, bus or trace 81, 811 or 812 may contain a patterned circuit layerover the patterned circuit layers 831 and/or 832 of the thick and widesignal trace, bus or plane 83 as shown in FIGS. 7B-7D. Alternatively,the thick and wide signal trace, bus or plane 83 as shown in FIGS. 7B-7Dmay contain a patterned circuit layer over that of the above-mentionedpower plane, bus or trace 81. The node Rs of the regulator or converter41 can be connected to the sources of the NMOS transistors 2115 and 2117of the memory cell 215, the sources of the NMOS transistors 2111 and2113 of the sense amplifier 214 and the sources of the NMOS transistors2103′ and 2103 of the receiver circuit 212′ through the above-mentionedground plane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C,over the passivation layer 5. The above-mentioned ground plane, bus ortrace 82 or 821 may contain a patterned circuit layer over the patternedcircuit layers 831 and/or 832 of the thick and wide signal trace, bus orplane 83 as shown in FIGS. 7B-7D. Alternatively, the thick and widesignal trace, bus or plane 83 as shown in FIGS. 7B-7D may contain apatterned circuit layer over that of the above-mentioned ground plane,bus or trace 82.

Referring to FIG. 5R, the node P of the regulator or converter 41 can beconnected to the sources of the PMOS transistors 2116 and 2118 of thememory cell 215, the sources of the PMOS transistors 2112 and 2114 ofthe sense amplifier 214, the sources of the PMOS transistors 2901′ and2902′ of the latch circuit 217′ and the sources of the PMOS transistors2104′ and 2104 of the internal receiver 212′ through the above-mentionedpower plane, bus or trace 81, 811 or 812, as shown in FIGS. 1B, 1C, 2B,2C, 3B, 3C and 3D, over the passivation layer 5. The above-mentionedpower plane, bus or trace 81, 811 or 812 may contain a patterned circuitlayer over the patterned circuit layers 831 and/or 832 of the thick andwide signal trace, bus or plane 83 as shown in FIGS. 7B-7D.Alternatively, the thick and wide signal trace, bus or plane 83 as shownin FIGS. 7B-7D may contain a patterned circuit layer over that of theabove-mentioned power plane, bus or trace 81. The node Rs of theregulator or converter 41 can be connected to the sources of the NMOStransistors 2115 and 2117 of the memory cell 215, the sources of theNMOS transistors 2111 and 2113 of the sense amplifier 214, the sourcesof the NMOS transistors 2903′ and 2904′ of the latch circuit 217′ andthe sources of the NMOS transistors 2103′ and 2103 of the internalreceiver 212′ through the above-mentioned ground plane, bus or trace 82or 821, as shown in FIGS. 1C, 2C and 3C, over the passivation layer 5.The above-mentioned ground plane, bus or trace 82 or 821 may contain apatterned circuit layer over the patterned circuit layers 831 and/or 832of the thick and wide signal trace, bus or plane 83 as shown in FIGS.7B-7D. Alternatively, the thick and wide signal trace, bus or plane 83as shown in FIGS. 7B-7D may contain a patterned circuit layer over thatof the above-mentioned ground plane, bus or trace 82.

Referring to FIG. 5S, another important application of the thick metalline, trace or plane 83 over the passivation layer 5 may be used totransport a precise analog signal. The thick metal line, trace or plane83 has low resistance and capacitance per unit length characteristicsand thereby offers a low signal distortion of analog signals. FIG. 5Sshows a circuit design with an over-passivation metal bus, trace or line83 connecting multiple analog circuits 21, 22, 23 and 24. The design issimilar to FIG. 5B except that the internal circuits 21, 22, 23 and 24are analog circuits, or mixed-mode circuits comprising an analog circuitand a digital circuit. The thick metal bus, trace or line 83 over thepassivation layer 5 connects the analog circuits 21, 22, 23 and 24. Ananalog signal output from the output node Yo of the analog circuit 21can be transmitted to the input node Ui′ of the internal circuit 22through the fine-line metal structure 631 under the passivation layer 5,then through the thick metal bus, trace or plane 83 over the passivationlayer 5, and then through the fine-line metal structures 632 a and 632 bunder the passivation layer 5. An analog signal output from the outputnode Yo of the analog circuit 21 can be transmitted to the input nodeVi′ of the internal circuit 23 through the fine-line metal structure 631under the passivation layer 5, then through the thick metal bus, traceor plane 83 over the passivation layer 5, and then through the fine-linemetal structures 632 a and 632 c under the passivation layer 5. Ananalog signal output from the output node Yo of the analog circuit 21can be transmitted to the input node Wi′ of the internal circuit 24through the fine-line metal structure 631 under the passivation layer 5,then through the thick metal bus, trace or plane 83 over the passivationlayer 5, and then through the fine-line metal structure 634 under thepassivation layer 5.

The analog circuits 21, 22, 23 and 24 can be an operational amplifier,amplifier, pre-amplifier, a power amplifier, an analog to digital (A/D)converter, a digital to analog (D/A) converter, a pulse reshapingcircuit, a switched capacitor filter, a RC filter, or other kind ofanalog circuits. FIG. 5T shows a case where the internal circuit 21 inFIG. 5S is an operational amplifier 218 with an output node Yo connectedto the metal interconnection lines or traces 83 over the passivationlayer 5. The operational amplifier 218 is designed based on a CMOStechnology, referring to “CMOS Digital Circuit Technology” by M. Shoji,published by Prentice-Hall, Inc, New Jersey in 1987. Differential analogsignals can be input into two input nodes Yi+ and Yi− of a differentialcircuit 219 provided in the operational amplifier 218 and with two n-MOStransistors 2125 and 2127 and two p-MOS transistors 2126 and 2128,wherein the input nodes Yi+ and Yi− are connected to the gates of thep-MOS transistors 2128 and 2126, respectively. The sources of the p-MOStransistors 2126 and 2128 are connected to a drain of a p-MOS transistor2132 that is controlled by a voltage at the node 2138 determined byresistance of a resistor 2134. The output of the differential circuit219 at the drains of the n-channel MOS transistor 2127 and the p-channelMOS transistor 2128 is connected to a gate of an n-channel MOStransistor 2135 and to a top electrode 21331 of the capacitor 2133. Anoutput node Yo is at a bottom electrode 21332 of the capacitor 2133, atthe drain of the n-channel MOS transistor 2135, and at a drain of thep-channel MOS transistor 2136. The p-MOS transistor 2136 is controlledby a voltage at the node 2138 determined by resistance of a resistor2134. Thereby, the voltage at the output node Yo is controlled by whatdegree the n-MOS transistor 2135 is turned on and by the output of thedifferential circuit 219. The capacitor 2133 are often used for ananalog circuit, and are usually formed by a MOS capacitor (using thepoly gate and the silicon substrate as two electrodes of the capacitor2133), or a poly-to-poly capacitor (using a first poly silicon and asecond poly silicon as two electrodes of the capacitor 2133). Thecapacitor 2133 may have a function to reduce a noise input from theinput nodes Yi+ and Yi−. The resistor 2134 is also often used for ananalog circuit, and is usually provided by an impurity-doped diffusionarea with doping density of 10¹⁵−10¹⁷/cm³, such as n well or p well, orof 10¹⁹−10²¹/cm³, such as N+ diffusion or P+ diffusion, in the siliconsubstrate, and/or an impurity-doped poly silicon. The circuit shown inFIG. 5T can output a voltage Yo proportionally amplifying thedifferential value of the input voltages Yi+ and Yi−.

The thick metal bus, trace or plane 83 and 83′ illustrated in FIGS.5B-5Z can be realized by forming the circuit metal layers 831 and/or 832and the polymer layers 95, 98 and/or 99 shown in FIGS. 7B-7D, or byforming the circuit metal layers 801 and/or 802 and the polymer layers95, 97, 98 and/or 99 shown in FIGS. 15A-21K.

Third Embodiment Complete Architecture of the Invention

The technology of forming the coarse metal conductor provides otheradvantages for the IC chip. The technology of manufacturing the coarsetrace, bus or plane 83 or 83′ over the passivation layer 5 may comprisesgold, copper, silver, palladium, rhodium, platinum, ruthenium, ornickel. Various kinds of contacting structures such as solder bumps,solder pads, solder balls, Au bumps, gold pads, Pd pads, Al pads, orwire bonding pads can be formed on the coarse trace, bus or plane 83 toconnect the IC chip to an external circuitry easily. In FIGS. 5B, 5K,5S, 7B, 7C and 7D, the thick metal trace, bus or plane 83 over thepassivation layer 5 are used to transport signals input to or outputfrom the internal circuits 21, 22, 23 or 24. The internal circuits 21,22, 23 or 24 are not connected to an external circuit through the thickmetal trace, bus or plane 83 over the passivation layer 5. Yet, an ICchip may be connected to and communicated with an external circuit. Whena signal is transmitted to external circuits or components, someoff-chip circuitry is required to (1) drive the large current load ofexternal circuits, parasitics or components, (2) detect noisy signalsfrom the external circuits or components, and (3) prevent the internalcircuits from being damaged by the surge electrical stimulus fromexternal circuits or components.

FIGS. 8B, 9B and 10B depict a schematic architecture according to athird preferred embodiment of the present invention. FIG. 8B shows acircuit diagram according to a third preferred embodiment of the presentinvention. FIG. 9B shows a top view realizing the circuit diagram ofFIG. 8B. FIG. 10B shows a cross-sectional view realizing the circuitdiagram of FIG. 8B.

Referring to FIGS. 8B, 9B and 10B, the off-chip I/O circuit 42 isconnected to the output node of the internal circuit 21 and to the inputnodes of the internal circuits 22, 23 and 24. A metal bump 89 for beingconnected to an external circuit may be formed on a redistributed pad8310. The redistributed metal trace 83 r over the passivation layer 5connects the redistributed pad 8310 to the original pad 6390 exposed byan opening 539 in the passivation layer 5, wherein the position of theredistributed pad 8310 from a top perspective view is different fromthat of the original pad 6390. The original pad 6390 is connected to theI/O circuit 42 and to the ESD circuit 43. A signal may be transmittedfrom the internal circuit 21 to an external circuitry through the thickmetal bus, trace or plane 83, then through the off-chip I/O circuit 42,and then through the thick metal bus, trace or plane 83 r; a signal maybe transmitted from an external circuit to the internal circuits 22, 23and/or 24 through the thick metal traces, buses or plane 83r, throughthe off-chip I/O circuit 42 and then through the thick metal bus, traceor plane 83; a signal may be transmitted from the internal circuit 21 tothe internal circuits 22, 23 and/or 24 through the thick metal bus,trace or plane 83.

The shape of the openings 531, 532, 534 and 539′ from a top perspectiveview may be round, square, rectangular or polygon. If the openings 531,532, 534 and 539′ are round, the openings 531, 532 and 534 may have adiameter of between 0.1 and 200 microns, between 1and 100 microns, or,preferably, between 0.1 and 30 microns. If the openings 531, 532 and 534are square, the openings 531, 532 and 534 may have a width of between0.1 and 200 microns, between 1 and 100 microns, or, preferably, between0.1 and 30 microns. If the openings 531, 532 and 534 are rectangular,the openings 531, 532 and 534 may have a width of between 0.1 and 200microns, between 1 and 100 microns, or, preferably, between 0.1 and 30microns, and a length of between 1 micron and 1 centimeter. If theopenings 531, 532 and 534 are polygon having more than five sides, theopenings 531, 532 and 534 have a greatest diagonal length of between 0.1and 200 microns, between 1 and 100 microns, or, preferably, between 0.1and 30 microns. Alternatively, the openings 531, 532 and 534 have agreatest transverse dimension of between 0.1 and 200 microns, between 1and 100 microns, or, preferably, between 0.1 and 30 microns. In a case,the openings 531, 532 and 534 have a width of between 0.1 and 30microns, with the lower portion of the openings 9531, 9532 and 9514 inthe polymer layer 95 having a width of between 20 and 100 microns.

Alternatively, referring to FIG. 8C, the element 42 may be an off-chipreceiver. The off-chip receiver 42 is connected to the input nodes ofthe internal circuits 21, 22, 23 and 24 through the thick metal bus,trace or plane 83.

Alternatively, referring to FIG. 8G, the element 42 may be an off-chipdriver. The off-chip driver 42 is connected only to the output nodes ofthe internal circuits 21, 22, 23 and 24 through the thick metal bus,trace or plane 83.

FIGS. 8B and 8C show a simplified circuitry diagram where a thick metaltrace 83 over a passivation layer 5 connects an off-chip I/O circuit 42,such as external driver or external receiver, and internal circuits 21,22, 23 and 24. FIG. 9B shows a top view of a semiconductor chiprealizing the circuitry shown in FIGS. 8B and 8C, wherein coarse traces83 and 83r shown in FIG. 9B mean the traces formed over the passivationlayer 5, and fine traces 69, 632 a, 632 b and 632 c shown in FIG. 9Bmean the traces formed under the passivation layer 5. FIG. 10B shows across-sectional view of a semiconductor chip realizing the circuitryshown in FIGS. 8B and 8C. FIG. 9B shows a top view of the semiconductorchip shown in FIG. 10B. FIGS. 8B, 9B, 10B, 10C, 10D and 10E show thecircuitry architecture of the invention using the two hierarchies of thefine-line IC metal structures 639, 639′, 631, 632, 634 and 69 under thepassivation layer 5 and the coarse metal traces 83, 831, 832 and 83 rover the passivation layer 5, with the consideration of whole chipdesign of the internal and external circuit connection.

Referring to FIGS. 8B, 9B and 10B, the internal circuit 21 may output asignal to other internal circuits 22, 23 and 24 through the thick metalbus, trace or plane 83 over the passivation layer 5, as described inFIGS. 5B-5J and 5S-5T, and, besides, the internal circuit 21 may outputa signal to an external circuit through, in sequence, the fine-linemetal trace 631 under the passivation layer 5, the thick metal trace 83over the passivation layer 5, the fine-line metal trace 639′ under thepassivation layer 5, the I/O circuit 42, such as external driver, thefine-line metal trace 69 under the passivation layer 5, theredistributed trace 83 r over the passivation layer 5 and the metal bump89 on the redistributed trace 83 r.

Referring to FIG. 8C, 9B and 10B, a signal output from the internalcircuit 24 may be transmitted to the internal circuit 21 through thethick metal bus, trace or plane 83′ over the passivation layer 5, asdescribed in FIGS. 5K-5R, and, besides, a signal output from an externalcircuit may be transmitted to the internal circuit 21 through the metalbump 89, the redistributed trace 83 r, the fine-line metal trace 69under the passivation layer 5, the I/O circuit 42, such as externalreceiver, the fine-line metal trace 639′ under the passivation layer 5,the thick metal bus, trace or plane 83′ over the passivation layer 5 andthe fine-line metal trace 631′ under the passivation layer 5. A signaloutput from the internal circuit 24 may be transmitted to the internalcircuit 22 through the thick metal bus, trace or plane 83′ over thepassivation layer 5, as described in FIGS. 5K-5R, and, besides, a signaloutput from an external circuit may be transmitted to the internalcircuit 22 through the metal bump 89, the redistributed trace 83 r, thefine-line metal trace 69 under the passivation layer 5, the I/O circuit42, such as external receiver, the fine-line metal trace 639′ under thepassivation layer 5, the thick metal bus, trace or plane 83′ over thepassivation layer 5, the fine-line metal trace 632 a′ and 632 b′ underthe passivation layer 5. A signal output from the internal circuit 24may be transmitted to the internal circuit 23 through the thick metalbus, trace or plane 83′ over the passivation layer 5, as described inFIGS. 5K-5R, and, besides, a signal output from an external circuit maybe transmitted to the internal circuit 23 through the metal bump 89, theredistributed trace 83 r, the fine-line metal trace 69 under thepassivation layer 5, the I/O circuit 42, such as external receiver, thefine-line metal trace 639′ under the passivation layer 5, the thickmetal bus, trace or plane 83′ over the passivation layer 5, thefine-line metal trace 632 a′ and 632 c′ under the passivation layer 5.

In this embodiment, referring to FIGS. 8B and 8C, a signal transmittedthrough the thick metal bus, trace or plane 83 or 83′ over thepassivation layer 5 in the internal scheme 200 can be transmitted to orfrom the external circuit (not shown) through an off-chip scheme 40including an I/O circuit 42, such external driver or receiver 42, and anESD (electro static discharge) circuit 43. The ESD circuit 43 isconnected in parallel with the I/O circuit 42 through the trace 69 underthe passivation layer 5. The redistributed metal trace 83 r can be usedfor redistribution of the IC fine-line metal (I/O) pads 6390 in FIG.10B, relocated to a different location, for example an over-passivationmetal pads 8310 in FIG. 10B, resulting in readily being connected to anexternal circuit, such as another semiconductor chip, ball-grid-array(BGA) substrate or ceramic substrate through the metal bump 89 orthrough a wirebonded wire bonded onto the pad 8310, to a flexiblesubstrate through the meal bump 89 preferably including a gold layerhaving a thickness of between 7 and 25 micrometers using a gold-to-goldbonding technology or using a gold-to-tin bonding technology, or to aglass substrate through the meal bump 89 preferably including a goldlayer having a thickness of between 7 and 25 micrometers via ananisotropic conductive film (ACF) or anisotropic conductive paste ACP.The redistributed metal line, trace or plane 83 r can be formed duringforming the over-passivation interconnection scheme 83.

Referring to FIG. 11F, the off-chip circuitry 40, in FIGS. 8B and 8C,for being connected to the external circuitry may include an ESD circuit43, composed of two diodes 4331 and 4332, and an I/O circuit 42.

In a first aspect, the I/O circuit 42 may be an off-chip driver 421, asshown in FIG. 11A, in application to the circuit architecture shown inFIG. 8B, having an input node F connected to the internal circuits 20through the thick and wide circuit trace 83, and an output node Econnected, in parallel with the ESD circuit 43, to the metal bump 89.FIG. 11A shows an example of a two-stage cascade off-chip driver 421,CMOS cascade driver. The cascade driver may comprise several stages ofinverters. The off-chip driver 421 may include two inverters 421′ and421″, wherein the inverter 421′ is composed of an NMOS device 4201 and aPMOS device 4202, and the inverter 421″ is composed of an NMOS device4203 and a PMOS device 4204. The gates of the PMOS device 4202 and theNMOS device 4201 serve as the input node F, and 4 the drains of the PMOSdevice 4204 and the NMOS device 4203 serve as the output node E. Thedrains of the PMOS device 4202 and the NMOS device 4201 are connected tothe gates of the PMOS device 4204 and the NMOS device 4203.

Referring to FIG. 11A, the above-mentioned power plane, bus or trace 81,811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, over thepassivation layer 5 can connect the node P of the regulator or converter41 and the sources of the PMOS devices 4202 and 4204. Theabove-mentioned power plane, bus or trace 81, 811 or 812 may contain apatterned circuit layer over the patterned circuit layers 831 and/or 832of the thick and wide signal trace, bus or plane 83 as shown in FIGS.10B-10D and 10G. Alternatively, the thick and wide signal trace, bus orplane 83 as shown in FIGS. 10B-10D and 10G may contain a patternedcircuit layer over that of the above-mentioned power plane, bus or trace81. The above-mentioned ground plane, bus or trace 82 or 821, as shownin FIGS. 1C, 2C and 3C, over the passivation layer 5 can connect thenode Rs of the regulator or converter 41 and the sources of the NMOSdevices 4201 and 4203. The above-mentioned ground plane, bus or trace 82or 821 may contain a patterned circuit layer over the patterned circuitlayers 831 and/or 832 of the thick and wide signal trace, bus or plane83 as shown in FIGS. 10B-10E and 10G. Alternatively, the thick and widesignal trace, bus or plane 83 as shown in FIGS. 10B-10E and 10G maycontain a patterned circuit layer over that of the above-mentionedground plane, bus or trace 82.

The first stage 421′ of the off-chip driver in FIG. 11A is an inverterwith the NMOS device 4201 having a ratio of a physical channel widththereof to a physical channel length thereof greater than those of allNMOS devices in the internal circuits 20 connected to the input node Fof the off-chip driver 421, and with the PMOS device 4202 having a ratioof a physical channel width thereof to a physical channel length thereofgreater than those of all PMOS devices in the internal circuits 20connected to the input node F of the off-chip driver 421. The NMOStransistor 4203 may have a ratio of a physical channel width thereof toa physical channel length thereof ranging from 20 to 20,000, andpreferably ranging from 30 to 3000. The PMOS transistor 4204 may have aratio of a physical channel width thereof to a physical channel lengththereof ranging from 40 to 40,000, and preferably ranging from 60 to600. The output current of an off-chip driver 421 is proportional to thenumber of stages and the size (W/L, MOS transistor's channel width tolength ratio, more precisely, the MOS effective channel width toeffective channel length ratio) of transistors used in each stage of theoff-chip driver. The off-chip driver 421 may output a driving current ofbetween 5 mA and 5 A and, preferably, between 10 mA and 100 mA.

Provided that the off-chip driver 421 shown in FIG. 11A is applied tothe circuit architecture shown in FIG. 8B for a power management chip,the NMOS transistor 4203 of the off-chip driver 421 may have a ratio ofa physical channel width thereof to a physical channel length thereofranging from 2,000 to 200,000, and preferably ranging from 2,000 to20,000. The PMOS transistor 4204 may have a ratio of a physical channelwidth thereof to a physical channel length thereof ranging from 4,000 to400,000, and preferably ranging from 4,000 to 40,000. The off-chipdriver 421 may output a driving current of between 500 mA and 50 A and,preferably, between 500 mA and 5 A.

In a second aspect, the I/O circuit 42 may be an off-chip receiver 422,as shown in FIG. 11B, in application to the circuit architecture shownin FIG. 8C, having an output node F connected to the internal circuits21, 22 and 23 through the thick and wide circuit trace 83, and an inputnode E connected, in parallel with the ESD circuit 43, to the metal bump89. FIG. 11B shows an example of a two-stage cascade off-chip receiver422, CMOS cascade receiver. The off-chip receiver 422 may receive asignal from an external circuitry through the metal bump 89 and outputan amplified signal to the internal circuits 21, 22 and 23 through thethick and wide trace or bus 83′. The first stage 422′, close to theexternal circuitry, of the off-chip receiver 422 is an inverter havingan NMOS device 4205 and a PMOS device 4206 with a size designed todetect a noisy external signal. The first stage receives a noisy signalat point E from the external circuits or components, such as signal fromanother chip. The second stage 422″ of the off-chip receiver 422 is alsoan inverter except that it is formed by a larger size of NMOS device4207 and PMOS device 4208. The second stage of the inverter is used torestore the integrity of the noisy external signal for the internalcircuit. The gates of the PMOS device 4205 and the NMOS device 4206serve as the input node E, and the drains of the PMOS device 4208 andthe NMOS device 4207 serve as the output node F. The drains of the PMOSdevice 4206 and the NMOS device 4205 are connected to the gates of thePMOS device 4208 and the NMOS device 4207.

Referring to FIG. 11B, the above-mentioned power plane, bus or trace 81,811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, over thepassivation layer 5 can connect the node P of the regulator or converter41 and the sources of the PMOS devices 4206 and 4208. Theabove-mentioned power plane, bus or trace 81, 811 or 812 may contain apatterned circuit layer over the patterned circuit layers 831 and/or 832of the thick and wide signal trace, bus or plane 83 as shown in FIGS.10B-10D and 10G. Alternatively, the thick and wide signal trace, bus orplane 83 as shown in FIGS. 10B-10D and 10G may contain a patternedcircuit layer over that of the above-mentioned power plane, bus or trace81. The above-mentioned ground plane, bus or trace 82 or 821, as shownin FIGS. 1C, 2C and 3C, over the passivation layer 5 can connect thenode Rs of the regulator or converter 41 and the sources of the NMOSdevices 4205 and 4207. The above-mentioned ground plane, bus or trace 82or 821 may contain a patterned circuit layer over the patterned circuitlayers 831 and/or 832 of the thick and wide signal trace, bus or plane83 as shown in FIGS. 10B-10E and 10G. Alternatively, the thick and widesignal trace, bus or plane 83 as shown in FIGS. 10B-10E and 10G maycontain a patterned circuit layer over that of the above-mentionedground plane, bus or trace 82.

The first stage 422′ of the off-chip receiver in FIG. 1B is an inverterwith the NMOS device 4205 having a ratio of a physical channel widththereof to a physical channel length thereof greater than those of allNMOS devices in the internal circuits 20 connected to the output node Fof the off-chip receiver 422, and with the PMOS device 4206 having aratio of a physical channel width thereof to a physical channel lengththereof greater than those of all PMOS devices in the internal circuits20 connected to the output node F of the off-chip receiver 422. The NMOStransistor 4207 may have a ratio of a physical channel width thereof toa physical channel length thereof ranging from 10 to 20,000, andpreferably ranging from 10 to 3000. The PMOS transistor 4208 may have aratio of a physical channel width thereof to a physical channel lengththereof ranging from 20 to 40,000, and preferably ranging from 20 to600. The off-chip receiver 422 may output a driving current of between 2mA and 5 A and, preferably, between 3 mA and 100 mA.

Provided that the off-chip receiver 422 shown in FIG. 11B is applied tothe circuit architecture shown in FIG. 8C for a power management chip,the NMOS transistor 4207 of the off-chip receiver 422 may have a ratioof a physical channel width thereof to a physical channel length thereofranging from 10 to 20,000, and preferably ranging from 10 to 3000. ThePMOS transistor 4208 may have a ratio of a physical channel widththereof to a physical channel length thereof ranging from 20 to 40,000,and preferably ranging from 20 to 600. The off-chip receiver 422 mayoutput a driving current of between 150 mA and 50 A and, preferably,between 150 mA and 5 A.

In a third aspect, the I/O circuit 42 may be a tri-state buffer 423, asshown in FIG. 11C, in application to the circuit architecture shown inFIG. 8B, having an input node F connected to the internal circuits 20through the thick and wide circuit trace 83, and an output node E, inparallel with the ESD circuit 43, connected to the metal bump 89. FIG.11C shows an example of an off-chip tri-state buffer 423; as an off-chipdriver, a common design in IC chips to allow multiple logic gates todrive the same output, such as a bus. The tri-state buffer 423, servingas an off-chip driver, may include two PMOS devices 4210 and 4212 andtwo NMOS devices 4209 and 4211. The gates of the PMOS device 4210 andthe NMOS device 4209 serve as the input node F, and the drains of thePMOS device 4212 and the NMOS device 4211 serve as the output node E.The drain of the PMOS device 4210 is connected to the source of the PMOSdevice 4212. The drain of the NMOS device 4209 is connected to thesource of the NMOS device 4211. The tri-state buffer 423 may have aswitch function controlled by an Enable signal transmitted to the gateof the NMOS device 4211 and an Enable(bar) signal transmitted to thegate of the PMOS device 4212. The off-chip tri-state buffer in FIG. 11Ccan be viewed as a gated inverter. When the enabling signal En is high (En is low), the off-chip tri-state buffer outputs a signal to anexternal circuit. When the signal En is set at low ( En is high), nosignal will be output to an external circuit. The off-chip tri-statebuffer 423 is set to drive the external data bus.

Referring to FIG. 11C, the above-mentioned power plane, bus or trace 81,811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, over thepassivation layer 5 can connect the node P of the regulator or converter41 and the source of the PMOS device 4210. The above-mentioned powerplane, bus or trace 81, 811 or 812 may contain a patterned circuit layerover the patterned circuit layers 831 and/or 832 of the thick and widesignal trace, bus or plane 83 as shown in FIGS. 10B-10D and 10G.Alternatively, the thick and wide signal trace, bus or plane 83 as shownin FIGS. 10B-10D and 10G may contain a patterned circuit layer over thatof the above-mentioned power plane, bus or trace 81. The above-mentionedground plane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C,over the passivation layer 5 can connect the node Rs of the regulator orconverter 41 and the source of the NMOS device 4209. The above-mentionedground plane, bus or trace 82 or 821 may contain a patterned circuitlayer over the patterned circuit layers 831 and/or 832 of the thick andwide signal trace, bus or plane 83 as shown in FIGS. 10B-10E and 10G.Alternatively, the thick and wide signal trace, bus or plane 83 as shownin FIGS. 10B-10E and 10G may contain a patterned circuit layer over thatof the above-mentioned ground plane, bus or trace 82.

The NMOS transistors 4209 and 4211 may have a ratio of a physicalchannel width thereof to a physical channel length thereof ranging from20 to 20,000, and preferably ranging from 30 to 3000. The PMOStransistors 4210 and 4212 may have a ratio of a physical channel widththereof to a physical channel length thereof ranging from 40 to 40,000,and preferably ranging from 60 to 600. The tri-state buffer 423 mayoutput a driving current of between 5 mA and 5 A and, preferably,between 10 mA and 100 mA.

Provided that the tri-state buffer 423 shown in FIG. 11A is applied tothe circuit architecture shown in FIG. 8B for a power management chip,the NMOS transistors 4209 and 4211 of the tri-state buffer 423 may havea ratio of a physical channel width thereof to a physical channel lengththereof ranging from 2,000 to 200,000, and preferably ranging from 2,000to 20,000. The PMOS transistors 4210and 4212 may have a ratio of aphysical channel width thereof to a physical channel length thereofranging from 4,000 to 400,000, and preferably ranging from 4,000 to40,000. The tri-state buffer 423 may output a driving current of between500 mA and 50 A and, preferably, between 500 mA and 5 A.

In a fourth aspect, the I/O circuit 42 may be a tri-state buffer 423, asshown in FIG. 11E, in application to the circuit architecture shown inFIG. 8C, having an output node F connected to the internal circuits 21,22 and 23 through the thick and wide circuit trace 83′, and an inputnode E, in parallel with the ESD circuit 43, connected to the metal bump89. FIG. 11E shows an example of an off-chip tri-state buffer 423, as anoff-chip receiver. The tri-state buffer 423, serving as an off-chipreceiver, may include two PMOS devices 4210 and 4212 and two NMOSdevices 4209 and 4211. The gates of the PMOS device 4210 and the NMOSdevice 4209 serve as the input node E, and the drains of the PMOS device4212 and the NMOS device 4211 serve as the output node F. The drain ofthe PMOS device 4210 is connected to the source of the PMOS device 4212.The drain of the NMOS device 4209 is connected to the source of the NMOSdevice 4211. The tri-state buffer 423 may have a switch functioncontrolled by an Enable signal transmitted to the gate of the NMOSdevice 4211 and an Enable(bar) signal transmitted to the gate of thePMOS device 4212. When the enabling signal En is high ( En is low), theoff-chip tri-state buffer outputs a signal to the internal circuits 20.When the signal En is set at low ( En is high), no signal will be outputto the internal circuits 20.

Referring to FIG. 11E, the above-mentioned power plane, bus or trace 81,811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, over thepassivation layer 5 can connect the node P of the regulator or converter41 and the source of the PMOS device 4210. The above-mentioned powerplane, bus or trace 81, 811 or 812 may contain a patterned circuit layerover the patterned circuit layers 831 and/or 832 of the thick and widesignal trace, bus or plane 83 as shown in FIGS. 10B-10D and 10G.Alternatively, the thick and wide signal trace, bus or plane 83 as shownin FIGS. 10B-10D and 10G may contain a patterned circuit layer over thatof the above-mentioned power plane, bus or trace 81. The above-mentionedground plane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C,over the passivation layer 5 can connect the node Rs of the regulator orconverter 41 and the source of the NMOS device 4209. The above-mentionedground plane, bus or trace 82 or 821 may contain a patterned circuitlayer over the patterned circuit layers 831 and/or 832 of the thick andwide signal trace, bus or plane 83 as shown in FIGS. 10B-10E and 10G.Alternatively, the thick and wide signal trace, bus or plane 83 as shownin FIGS. 10B-10E and 10G may contain a patterned circuit layer over thatof the above-mentioned ground plane, bus or trace 82.

The NMOS transistors 4209 and 4211 may have a ratio of a physicalchannel width thereof to a physical channel length thereof ranging from20 to 20,000, and preferably ranging from 30 to 3000. The PMOStransistors 4210 and 4212 may have a ratio of a physical channel widththereof to a physical channel length thereof ranging from 40 to 40,000,and preferably ranging from 60 to 600. The tri-state buffer 423 mayoutput a driving current of between 5 mA and 5 A and, preferably,between 10 mA and 100 mA.

Provided that the tri-state buffer 423 shown in FIG. 11E is applied tothe circuit architecture shown in FIG. 8C for a power management chip,the NMOS transistors 4209 and 4211 of the tri-state buffer 423 may havea ratio of a physical channel width thereof to a physical channel lengththereof ranging from 2,000 to 200,000, and preferably ranging from 2,000to 20,000. The PMOS transistors 4210 and 4212 may have a ratio of aphysical channel width thereof to a physical channel length thereofranging from 4,000 to 400,000, and preferably ranging from 4,000 to40,000. The tri-state buffer 423 may output a driving current of between500 mA and 50 A and, preferably, between 500 mA and 5 A.

There may be various off-chip input and output buffers. The aboveexamples are for the CMOS level signals. If the external signal is atransistor-transistor logic (TTL) level, a CMOS/TTL buffer is required.If the external signal is an emitter coupled logic (ECL) level, aCMOS/ECL interface buffer is required. One or more stages of inverterscan be added between the internal circuits 20 and the off-chip tri-statebuffer 423 serving as an off-chip driver as shown in FIG. 11C or as anoff-chip receiver as shown in FIG. 11E.

In a fifth aspect, the off-chip I/O circuit 42 may be an off-chip driver421 composed of a first level of inverter 421′ and a second level ofinverters 421″, as shown in FIG. 11D, in application to the circuitarchitecture shown in FIG. 8B, wherein the first level of inverter 421′is connected in series to the second level of inverters 421″, and thesecond level of inverters 421″ are connected in parallel with oneanother to the first level of inverter 421′. FIG. 8E shows a circuitrydiagram with the off-driver 421 of FIG. 11D applied to the circuitarchitecture shown in FIG. 8C. FIG. 9C shows a top perspective viewrealizing the circuit diagram of FIG. 8E. FIG. 10H shows a chipstructure realizing the circuit diagram of FIG. 8E. The off-chip driver421 has an input node F connected to the internal circuits 20 throughthe thick and wide circuit trace 83, and an output node E connected, inparallel with the ESD circuit 43, to the metal bump 89. The gates of thePMOS device and the NMOS device in the first level of inverter 421′serve as the input node F, and the drains of the PMOS devices and theNMOS devices in the second level of inverters 421″ serve as the outputnode E. The drains of the PMOS device and the NMOS device in the firstlevel of inverter 421′ are connected to the gates of the PMOS devicesand the NMOS devices in the second level of inverters 421″ through athick and wide metal trace or bus 83 s over the passivation layer 5. Thedrains of the PMOS devices and the NMOS devices in the second level ofinverters 421″ are connected to the metal bump 89 through a thick andwide metal trace or bus 83 r over the passivation layer 5. A patternedcircuit layer 831 formed on the polymer layer 95, such as polyimide,having a thickness of between 2 and 30 micrometers may be composed ofthe thick and wide metal traces or buses 83 r, 83 s and 83, that is, thethick and wide metal traces or buses 83 r, 83 s and 83 may be formed atthe same time, as shown in FIG. 10H.

Alternatively, multiple patterned circuit layers and multiple polymerlayers may be formed over the passivation layer 5, one of the polymerlayers is between neighboring two of the patterned circuit layers. Thethick and wide metal traces or buses 83 s may be formed in the lower oneof the patterned circuit layers, and the thick and wide metal traces orbuses 83 s may be formed in the upper one of the patterned circuitlayers and over the thick and wide metal traces or buses 83 s. The thickand wide metal traces or buses 83 may have a portion in the lower one ofthe patterned circuit layers and another portion in the upper one of thepatterned circuit layers.

Referring to FIG. 11D, the above-mentioned power plane, bus or trace 81,811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, over thepassivation layer 5 can connect the node P of the regulator or converter41 to the source of the PMOS device in the first level of inverter 421′and to the sources of the PMOS devices in the second level of inverter421″. The above-mentioned power plane, bus or trace 81, 811 or 812 maycontain a patterned circuit layer over the patterned circuit layer 831of the thick and wide signal trace, bus or plane 83 as shown in FIG.10H. Alternatively, the thick and wide signal trace, bus or plane 83 asshown in FIG. 10H may contain a patterned circuit layer over that of theabove-mentioned power plane, bus or trace 81. The above-mentioned groundplane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C, over thepassivation layer 5 can connect the node Rs of the regulator orconverter 41, the source of the NMOS device in the first level ofinverter 421′, and the sources of the NMOS devices in the second levelof inverters 421″. The above-mentioned ground plane, bus or trace 82 or821 may contain a patterned circuit layer over the patterned circuitlayer 831 of the thick and wide signal trace, bus or plane 83 as shownin FIG. 10H. Alternatively, the thick and wide signal trace, bus orplane 83 as shown in FIG. 10H may contain a patterned circuit layer overthat of the above-mentioned ground plane, bus or trace 82.

Each of the NMOS transistors in the second level of inverters 421″ mayhave a ratio of a physical channel width thereof to a physical channellength thereof ranging from 20 to 20,000, and preferably ranging from 30to 3000, greater than that of NMOS transistor in the first levelinverter 421′ by between 1.5 times and 5 times, and preferably bynatural exponential times. Each of the PMOS transistors in the secondlevel of inverters 421″ may have a ratio of a physical channel widththereof to a physical channel length thereof ranging from 40 to 40,000,and preferably ranging from 60 to 600, greater than that of PMOStransistor in the first level inverter 421′ by between 1.5 times and 5times, and preferably by natural exponential times. The off-chip driver421 may output a driving current of between 5 mA and 5 A and,preferably, between 10 mA and 100 mA to an external circuit through themetal bump 89.

Provided that the off-chip driver 421 shown in FIG. 11D is applied tothe circuit architecture shown in FIG. 8B for a power management chip,each of the NMOS transistors in the second level of inverters 421″ mayhave a ratio of a physical channel width thereof to a physical channellength thereof ranging from 2,000 to 200,000, and preferably rangingfrom 2,000 to 20,000. Each of the PMOS transistors in the second levelof inverters 421″ may have a ratio of a physical channel width thereofto a physical channel length thereof ranging from 4,000 to 400,000, andpreferably ranging from 4,000 to 40,000. The off-chip driver 421 mayoutput a driving current of between 500 mA and 50 A and, preferably,between 500 mA and 5 A to an external circuit through the metal bump 89.

In a sixth aspect, the off-chip I/O circuit 42 may be an off-chip driver421 composed of a first level of inverter 421′, a second level ofinverters 421″, a third level of inverter 421′″ and a fourth level ofinverter 421′″, as shown in FIG. 11G in application to the circuitarchitecture shown in FIG. 8B, wherein the first level of inverter 421′is connected in series to the second level of inverters 421″, the secondlevel of inverter 421″ is connected in series to the third level ofinverters 421′″, and the third level of inverter 421′ is connected inseries to the fourth level of inverters 421″″. FIG. 8F shows a circuitrydiagram with the off-driver 421 of FIG. 11G applied to the circuitarchitecture shown in FIG. 8C. FIG. 9D shows a top perspective viewrealizing the circuit diagram of FIG. 8F. FIG. 10I shows a chipstructure realizing the circuit diagram of FIG. 8F. The off-chip driver421 has an input node F connected to the internal circuits 20 throughthe thick and wide circuit trace 83, and an output node E connected, inparallel with the ESD circuit 43, to the metal bump 89. The gates of thePMOS device and the NMOS device in the first level of inverter 421′serve as the input node F, and the drains of the PMOS device and theNMOS device in the fourth level of inverter 421″″ serve as the outputnode E. The drains of the PMOS device and the NMOS device in the firstlevel of inverter 421′ are connected to the gates of the PMOS device andthe NMOS device in the second level of inverter 421″ through a fine-linemetal trace or bus under the passivation layer 5. The drains of the PMOSdevice and the NMOS device in the second level of inverter 421″ areconnected to the gates of the PMOS device and the NMOS device in thethird level of inverter 421′″ through a fine-line metal trace or busunder the passivation layer 5. The drains of the PMOS device and theNMOS device in the third level of inverter 421′″ are connected to thegates of the PMOS device and the NMOS device in the fourth level ofinverter 421″″ through a fine-line metal trace or bus under thepassivation layer 5. The drains of the PMOS device and the NMOS devicein the fourth level of inverters 421″″ are connected to the metal bump89 through the thick and wide metal trace or bus 83 r over thepassivation layer 5. A patterned circuit layer 831 formed on the polymerlayer 95, such as polyimide, having a thickness of between 2 and 30micrometers may be composed of the thick and wide metal traces or buses83 r and 83, that is, the thick and wide metal traces or buses 83 r and83 may be formed at the same time, as shown in FIG. 10I.

Referring to FIG. 11G, the above-mentioned power plane, bus or trace 81,811 or 812, as shown in FIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, over thepassivation layer 5 can connect the node P of the regulator or converter41 to the source of the PMOS device in the first level of inverter 421′,to the source of the PMOS device in the second level of inverter 421″,to the source of the PMOS device in the third level of inverter 421′″and to the source of the PMOS device in the fourth level of inverter421″″. The above-mentioned power plane, bus or trace 81, 811 or 812 maycontain a patterned circuit layer over the patterned circuit layer 831of the thick and wide signal trace, bus or plane 83 as shown in FIG.10I. Alternatively, the thick and wide signal trace, bus or plane 83 asshown in FIG. 10I may contain a patterned circuit layer over that of theabove-mentioned power plane, bus or trace 81. The above-mentioned groundplane, bus or trace 82 or 821, as shown in FIGS. 1C, 2C and 3C, over thepassivation layer 5 can connect the node Rs of the regulator orconverter 41, the source of the NMOS device in the first level ofinverter 421′, the source of the NMOS device in the second level ofinverter 421″, the source of the NMOS device in the third level ofinverter 421′″, and the source of the NMOS device in the fourth level ofinverter 421″″. The above-mentioned ground plane, bus or trace 82 or 821may contain a patterned circuit layer over the patterned circuit layer831 of the thick and wide signal trace, bus or plane 83 as shown in FIG.10I. Alternatively, the thick and wide signal trace, bus or plane 83 asshown in FIG. 10I may contain a patterned circuit layer over that of theabove-mentioned ground plane, bus or trace 82.

The NMOS transistor in the fourth level of inverter 421″″ may have aratio of a physical channel width thereof to a physical channel lengththereof greater than that of the NMOS transistor in the third level ofinverter 421′″ by between 1.5 and 5 times, and preferably by naturalexponential times, that is greater than that of the NMOS transistor inthe second level of inverter 421″ by between 1.5 and 5 times, andpreferably by natural exponential times, that is greater than that ofthe NMOS transistor in the first level of inverter 421′ by between 1.5and 5 times, and preferably by natural exponential times. The PMOStransistor in the fourth level of inverter 421″″ may have a ratio of aphysical channel width thereof to a physical channel length thereofgreater than that of the PMOS transistor in the third level of inverter421′″ by between 1.5 and 5 times, and preferably by natural exponentialtimes, that is greater than that of the PMOS transistor in the secondlevel of inverter 421″ by between 1.5 and 5 times, and preferably bynatural exponential times, that is greater than that of the PMOStransistor in the first level of inverter 421′ by between 1.5 and 5times, and preferably by natural exponential times. The off-chip driver421 may output a driving current of between 5 mA and 5 A and,preferably, between 10 mA and 100 mA to an external circuit through themetal bump 89.

The NMOS transistor in the fourth level of inverter 421″″ may have aratio of a physical channel width thereof to a physical channel lengththereof ranging from 20 to 20,000, and preferably ranging from 30 to3000. The PMOS transistor in the fourth level of inverter 421″″ may havea ratio of a physical channel width thereof to a physical channel lengththereof ranging from 40 to 40,000, and preferably ranging from 60 to600. The NMOS transistor in the third level of inverter 421′″ may have aratio of a physical channel width thereof to a physical channel lengththereof ranging from 7 to 7,000, and preferably ranging from 10 to 100.The PMOS transistor in the third level of inverter 421′″ may have aratio of a physical channel width thereof to a physical channel lengththereof ranging from 13 to 13,000, and preferably ranging from 20 to200. The NMOS transistor in the second level of inverter 421 ″ may havea ratio of a physical channel width thereof to a physical channel lengththereof ranging from 2 to 2,000, and preferably ranging from 3 to 30.The PMOS transistor in the second level of inverter 421″ may have aratio of a physical channel width thereof to a physical channel lengththereof ranging from 4 to 4,000, and preferably ranging from 6 to 70.

Provided that the off-chip driver 421 shown in FIG. 11D is applied tothe circuit architecture shown in FIG. 8B for a power management chip,the NMOS transistor in the fourth level of inverter 421″″ may have aratio of a physical channel width thereof to a physical channel lengththereof ranging from 2,000 to 200,000, and preferably ranging from 2,000to 20,000. The PMOS transistor in the fourth level of inverter 421″″ mayhave a ratio of a physical channel width thereof to a physical channellength thereof ranging from 4,000 to 400,000, and preferably rangingfrom 4,000 to 40,000. The NMOS transistor in the third level of inverter421′″ may have a ratio of a physical channel width thereof to a physicalchannel length thereof ranging from 700 to 70,000, and preferablyranging from 700 to 7,000. The PMOS transistor in the third level ofinverter 421′″ may have a ratio of a physical channel width thereof to aphysical channel length thereof ranging from 1,3000 to 130,000, andpreferably ranging from 1,3000 to 13,000. The NMOS transistor in thesecond level of inverter 421″ may have a ratio of a physical channelwidth thereof to a physical channel length thereof ranging from 230 to23,000, and preferably ranging from 230 to 2,3000. The PMOS transistorin the second level of inverter 421″ may have a ratio of a physicalchannel width thereof to a physical channel length thereof ranging from400 to 40,000, and preferably ranging from 400 to 4,000. The off-chipdriver 421 may output a driving current of between 500 mA and 50 A and,preferably, between 500 mA and 5 A to an external circuit through themetal bump 89.

Referring to FIGS. 8B, 8C, 8E and 8F, the off-chip I/O circuit 42 isconnected, in parallel with the ESD circuit 43, to the metal bump 89.The detail of the ESD circuit 43 may be referred to as FIG. 11F. The ESDcircuit 43 is composed of two reverse-biased diodes 4331 and 4332,wherein the node E is connected to the anode of the diode 4332, to thecathode of the diode 4331, to the off-chip I/O circuit 42, such asoff-chip driver 421 of FIG. 11A, 11D or 11G, off-chip receiver 422 ofFIG. 11B, or tri-state buffer 423 of FIG. 11C or 11E, and to the metalbump 89. The diode 4331 is reverse-biased between an external voltageand the ground voltage Vss, and the diode 4332 is reverse-biased betweenthe external voltage and the power voltage Vdd or Vcc.

Referring to FIG. 11F, an external power voltage Vdd can be provided tothe cathode of the diode 4332 through a power bus or plane over thepassivation layer 5. The above-mentioned ground plane, bus or trace 82or 821, as shown in FIGS. 1C, 2C and 3C, over the passivation layer 5can connect the node Rs of the regulator or converter 41 and the cathodeof the diode 4331.

Thereby, the voltage at the node E can be clamped between the powervoltage Vdd input from an external circuit and the ground voltage Vss orbetween the power voltage Vdd and the ground voltage Vss. When thevoltage at the node E suddenly exceeds the power voltage Vdd, a currentwill discharge from the node E to the external circuit through the diode4332. When the voltage at the node E dramatically drop under the groundvoltage Vss, a current will flow from the external circuit to the node Ethrough the diode 4331.

Alternatively, the node E in the circuitry diagrams in FIGS. 8B, 8C, 8Eand 8F can be protected by multiple ESD circuits 43, which can bereferred to as FIG. 11H. For example, referring to FIG. 8D, the node Econnecting the off-chip driver 42 to the metal bump 89 may be protectedby multiple ESD circuits 43. Each of the ESD circuits 43 is composed oftwo reverse-biased diodes 4331 and 4332, wherein the node E is connectedto the anodes of the diodes 4332, to the cathodes of the diodes 4331, tothe off-chip I/O circuit 42, such as off-chip driver 421 of FIG. 11A,11D or 11G off-chip receiver 422 of FIG. 11B, or tri-state buffer 423 ofFIG. 11C or 11E, and to the metal bump 89. The diodes 4331 arereverse-biased between an external voltage and the ground voltage Vss,and the diodes 4332 are reverse-biased between the external voltage andthe power voltage Vdd or Vcc.

Referring to FIG. 11H, an external power voltage Vdd can be provided tothe cathodes of the diodes 4332 through a power bus or plane over thepassivation layer 5. The above-mentioned ground plane, bus or trace 82or 821, as shown in FIGS. 1C, 2C and 3C, over the passivation layer 5can connect the node Rs of the regulator or converter 41 and thecathodes of the diodes 4331.

Thereby, the voltage at the node E can be clamped between the powervoltage Vdd input from an external circuit and the ground voltage Vss.When the voltage at the node E suddenly exceeds the power voltage Vdd, acurrent will discharge from the node E to the external circuit throughthe diodes 4332. When the voltage at the node E dramatically drop underthe ground voltage Vss, a current will flow from the external circuit tothe node E through the diodes 4331.

In FIGS. 10B, 10D, 10C; 10H and 10I, there is only one patterned circuitlayer 831, including a portion serving as the above-mentioned thick andwide metal trace 83 and another portion serving as the above-mentionedthick and wide metal trace 83 r, over the passivation layer 5. Thepatterned circuit layer 831 may contain an adhesion/barrier layer, aseed layer on the adhesion/barrier layer, and an electroplated metallayer 8312 on the seed layer, the adhesion/barrier layer and the seedlayer composing the bottom layer 8311.

Referring to FIG. 10B, regards to the process for forming the patternedcircuit layer 831, the adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on asilicon-nitride layer of the passivation layer 5 and on contact pads6390, principally made of aluminum or copper, exposed by multipleopenings 539, 539′, 531, 532 and 534 in the passivation layer 5.Thereafter, the seed layer may be formed by sputtering a copper layerhaving a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material or by sputteringa gold layer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material. Thereafter, aphotoresist layer may be formed on the seed layer, multiple openings inthe photoresist layer exposing the seed layer. Thereafter, the metallayer 8312 may be formed by electroplating a copper layer having athickness between 2 and 30 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer, byelectroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer and then electroplating a nickellayer having a thickness between 0.5 and 10 micrometers on theelectroplated copper layer in the openings in the photoresist layer, byelectroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer, electroplating a nickel layerhaving a thickness between 0.5 and 10 micrometers on the electroplatedcopper layer in the openings in the photoresist layer and thenelectroplating a gold layer, platinum layer, palladium layer orruthenium layer having a thickness between 0.05 and 2 micrometers on theelectroplated nickel layer in the openings in the photoresist layer, orby electroplating a gold layer having a thickness between 2 and 30micrometers on the gold layer serving as the seed layer, exposed by theopenings in the photoresist layer. Thereafter, the photoresist layer maybe removed. Thereafter, the seed layer not under the metal layer 8312 isremoved using a wet-etching process or using a dry-etching process.Thereafter, the adhesion/barrier layer not under the metal layer 8312 isremoved using a wet-etching process or using a dry-etching process.

After the patterned circuit layer 831 is formed, a polymer layer 99 canbe formed by spin-on coating a negative photosensitive polyimide layer,such as ester type, on the patterned circuit layer 831 and on thenitride layer of the passivation layer 5, exposing the spin-on coatedphotosensitive polyimide layer, developing the exposed polyimide layerand then curing the developed polyimide layer at the temperature between265 and 285° C. for a time between 30 and 240 minutes in a nitrogen oroxygen-free ambient. Thereby, an opening 9939 may be formed in thepolymer layer 99, exposing a contact pad 8310 of the patterned circuitlayer 831.

Referring to FIG. 10B, for forming the metal bump 89 over the contactpad 8310, an adhesion/barrier layer may be formed by sputtering atitanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 99 and on the contact pad 8310 exposed by the opening9939. Thereafter, the seed layer may be formed by sputtering a copperlayer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material. Thereafter, aphotoresist layer may be formed on the seed layer, multiple openings inthe photoresist layer exposing the seed layer. Thereafter, the metalbump 89 may be formed by electroplating a copper layer having athickness between 0.5 and 10 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer,electroplating a nickel layer having a thickness between 0.5 and 10micrometers on the electroplated copper layer in the openings in thephotoresist layer, and then electroplating a tin-containing layer, suchas a tin-lead alloy, a tin-silver alloy or a tin-silver-copper alloy,having a thickness between 60 and 200 micrometers on the electroplatednickel layer in the openings in the photoresist layer. Thereafter, thephotoresist layer may be removed. Thereafter, the seed layer not underthe metal bump 89 is removed using a wet-etching process or using adry-etching process. Thereafter, the adhesion/barrier layer not underthe metal bump 89 is removed using a wet-etching process or using adry-etching process. Thereafter, the metal bump 89 can be reflowed to beshaped like a ball for a flip-chip assembly. The metal bump 89 can beconnected to a printed circuit board, ceramic substrate or anothersemiconductor chip.

Referring to FIG. 10B, for forming another kind of metal bump 89 overthe contact pad 8310, an adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, or sputtering a tantalum-containing layer, such as tantalumlayer or tantalum-nitride layer, having a thickness between 1000 and6000 angstroms, on the polymer layer 99 and on the contact pad 8310exposed by the opening 9939. Thereafter, the seed layer may be formed bysputtering a gold layer having a thickness between 200 and 3000angstroms on the adhesion/barrier layer of any above-mentioned material.Thereafter, a photoresist layer may be formed on the seed layer,multiple openings in the photoresist layer exposing the seed layer.Thereafter, the metal bump 89 may be formed by electroplating a goldlayer having a thickness between 6 and 25 micrometers on the gold layerserving as the seed layer, exposed by the openings in the photoresistlayer. Thereafter, the photoresist layer may be removed. Thereafter, theseed layer not under the metal bump 89 is removed using a wet-etchingprocess or using a dry-etching process. Thereafter, the adhesion/barrierlayer not under the metal bump 89 is removed using a wet-etching processor using a dry-etching process. The metal bump 89 can be connected to aflexible substrate by a tape-automated bonding (TAB) process, or a glasssubstrate via anisotropic conductive film or paste (ACF or ACP).

Alternatively, referring to FIG. 10B, a nickel layer having a thicknessbetween 0.05 and 2 micrometers can be electroless plated on the contactpad 8310 exposed by the opening 9939, and a gold layer, platinum layer,palladium layer or ruthenium layer having a thickness between 0.05 and 2micrometers can be electroless plated on the electroless plated nickellayer in the opening 9939 in the polymer layer 99. Thereafter, a goldwire can be bonded onto the electroless plated gold layer in the opening9939 in the polymer layer 99 using a wirebonding process.

Alternatively, referring to FIG. 10B, a gold wire can be bonded onto agold layer, platinum layer, palladium layer or ruthenium layer of thepatterned circuit layer 831, exposed by the openings 9939 in the polymerlayer 99 using a wirebonding process.

Alternatively, referring to FIG. 10C, there may be multiple patternedcircuit layers 831 and 832, including a portion serving as theabove-mentioned thick and wide metal trace 83 and another portionserving as the above-mentioned thick and wide metal trace 83 r, over thepassivation layer 5. The process for forming the patterned circuit layer831 shown in FIG. 10C can be referred to as the process for forming thepatterned circuit layer 831 shown in FIG. 10B. The patterned circuitlayer 832 may contain an adhesion/barrier layer, a seed layer on theadhesion/barrier layer, and an electroplated metal layer 8322 on theseed layer, the adhesion/barrier layer and the seed layer composing thebottom layer 8321.

Referring to FIG. 10C, after the patterned circuit layer 831 is formed,a polymer layer 98 can be formed by spin-on coating a negativephotosensitive polyimide layer, such as ester type, on the patternedcircuit layer 831 and on the nitride layer of the passivation layer 5,exposing the spin-on coated photosensitive polyimide layer, developingthe exposed polyimide layer and then curing the developed polyimidelayer at the temperature between 265 and 285° C. for a time between 30and 240 minutes in a nitrogen or oxygen-free ambient. Thereby, multipleopenings 9831, 9834 and 9839 may be formed in the polymer layer 98,exposing multiple contact pads of the patterned circuit layer 831.

Referring to FIG. 10C, regards to the process for forming the patternedcircuit layer 832, the adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 98 and on the contact pads of the patterned circuit layer831 exposed by multiple openings 9839, 9831 and 9834 in the polymerlayer 98. Thereafter, the seed layer may be formed by sputtering acopper layer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material or by sputteringa gold layer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material. Thereafter, aphotoresist layer may be formed on the seed layer, multiple openings inthe photoresist layer exposing the seed layer. Thereafter, the metallayer 8322 may be formed by electroplating a copper layer having athickness between 2 and 30 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer, byelectroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer and then electroplating a nickellayer having a thickness between 0.5 and 10 micrometers on theelectroplated copper layer in the openings in the photoresist layer, byelectroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer, electroplating a nickel layerhaving a thickness between 0.5 and 10 micrometers on the electroplatedcopper layer in the openings in the photoresist layer and thenelectroplating a gold layer, platinum layer, palladium layer orruthenium layer having a thickness between 0.05 and 2 micrometers on theelectroplated nickel layer in the openings in the photoresist layer, orby electroplating a gold layer having a thickness between 2 and 30micrometers on the gold layer serving as the seed layer, exposed by theopenings in the photoresist layer. Thereafter, the photoresist layer maybe removed. Thereafter, the seed layer not under the metal layer 8322 isremoved using a wet-etching process or using a dry-etching process.Thereafter, the adhesion/barrier layer not under the metal layer 8322 isremoved using a wet-etching process or using a dry-etching process.

After the patterned circuit layer 832 is formed, a polymer layer 99 canbe formed by spin-on coating a negative photosensitive polyimide layer,such as ester type, on the patterned circuit layer 832 and on thepolymer layer 98, exposing the spin-on coated photosensitive polyimidelayer, developing the exposed polyimide layer and then curing thedeveloped polyimide layer at the temperature between 265 and 285° C. fora time between 30 and 240 minutes in a nitrogen or oxygen-free ambient.Thereby, an opening 9939′ may be formed in the polymer layer 99,exposing a contact pad 8320 of the patterned circuit layer 832.

Referring to FIG. 10C, for forming the metal bump 89 over the contactpad 8320, an adhesion/barrier layer may be formed by sputtering atitanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 99 and on the contact pad 8320 exposed by the opening9939′. Thereafter, the seed layer may be formed by sputtering a copperlayer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material. Thereafter, aphotoresist layer may be formed on the seed layer, multiple openings inthe photoresist layer exposing the seed layer. Thereafter, the metalbump 89 may be formed by electroplating a copper layer having athickness between 0.5 and 10 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer,electroplating a nickel layer having a thickness between 0.5 and 10micrometers on the electroplated copper layer in the openings in thephotoresist layer, and then electroplating a tin-containing layer, suchas a tin-lead alloy, a tin-silver alloy or a tin-silver-copper alloy,having a thickness between 60 and 200 micrometers on the electroplatednickel layer in the openings in the photoresist layer. Thereafter, thephotoresist layer may be removed. Thereafter, the seed layer not underthe metal bump 89 is removed using a wet-etching process or using adry-etching process. Thereafter, the adhesion/barrier layer not underthe metal bump 89 is removed using a wet-etching process or using adry-etching process. Thereafter, the metal bump 89 can be reflowed to beshaped like a ball. The metal bump 89 can be connected to a printedcircuit board, ceramic substrate or another semiconductor chip.

Referring to FIG. 10C, for forming another kind of metal bump 89 overthe contact pad 8320, an adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, or sputtering a tantalum-containing layer, such as tantalumlayer or tantalum-nitride layer, having a thickness between 1000 and6000 angstroms, on the polymer layer 99 and on the contact pad 8320exposed by the opening 9939′. Thereafter, the seed layer may be formedby sputtering a gold layer having a thickness between 200 and 3000angstroms on the adhesion/barrier layer of any above-mentioned material.Thereafter, a photoresist layer may be formed on the seed layer,multiple openings in the photoresist layer exposing the seed layer.Thereafter, the metal bump 89 may be formed by electroplating a goldlayer having a thickness between 6 and 25 micrometers on the gold layerserving as the seed layer, exposed by the openings in the photoresistlayer. Thereafter, the photoresist layer may be removed. Thereafter, theseed layer not under the metal bump 89 is removed using a wet-etchingprocess or using a dry-etching process. Thereafter, the adhesion/barrierlayer not under the metal bump 89 is removed using a wet-etching processor using a dry-etching process. The metal bump 89 can be connected to aflexible substrate by a tape-automated bonding (TAB) process, or a glasssubstrate via anisotropic conductive film or paste (ACF or ACP).

Alternatively, referring to FIG. 10C, a nickel layer having a thicknessbetween 0.05 and 2 micrometers can be electroless plated on the contactpad 8320 exposed by the opening 9939′ in layer polymer layer 99, and agold layer, platinum layer, palladium layer or ruthenium layer having athickness between 0.05 and 2 micrometers can be electroless plated onthe electroless plated nickel layer in the opening 9939′ in the polymerlayer 99. Thereafter, a gold wire can be bonded onto the electrolessplated gold layer in the opening 9939′ in the polymer layer 99 using awirebonding process.

Alternatively, referring to FIG. 10C, a gold wire can be bonded onto agold layer, platinum layer, palladium layer or ruthenium layer of thepatterned circuit layer 832, exposed by the openings 9939′ in thepolymer layer 99 using a wirebonding process.

Referring to FIGS. 10D and 10E, before the patterned circuit layer 831is formed, a polymer layer 95 can be optionally formed by spin-oncoating a negative photosensitive polyimide layer, such as ester type,on the nitride layer of the passivation layer 5 and on the contact pads6390, exposing the spin-on coated photosensitive polyimide layer,developing the exposed polyimide layer and then curing the developedpolyimide layer at the temperature between 265 and 285° C. for a timebetween 30 and 240 minutes in a nitrogen or oxygen-free ambient.Thereby, multiple openings 9539, 9539′, 9531, 9532 and 9534 may beformed in the polymer layer 95, exposing multiple contact pads 6390exposed by the openings 539, 539′, 531, 532 and 533 in the passivationlayer 5. After the polymer layer 95 is formed, the patterned circuitlayer 831 can be formed on the polymer layer 95 and on the contact pads6390 exposed by the openings 539, 539′, 531, 532 and 533. Theadhesion/barrier layer of any above-mentioned material may be sputteredon the polymer layer 95 and on the contact pads 6390 exposed by theopenings 9539, 9539′, 9531, 9532 and 9534 in the polymer layer 95.

Alternatively, referring to FIG. 10F, the off-chip I/O circuit 42, suchas off-chip driver of FIGS. 11A, 11D or 11E, off-chip receiver of FIG.11B or tri-state buffer of FIGS. 11C or 11E, can be connected to theinternal circuits 20 through the fine-line metal trace 638 under thepassivation layer 5 but not through any trace or bus over thepassivation layer 5. There may be only one patterned circuit layer 831including a portion serving as the above-mentioned thick and wide metaltrace 83 r, over the passivation layer 5. The position of aredistributed pad 8310 of the above-mentioned thick and wide metal trace83 r for being wirebonded thereto from a top perspective view isdifferent from that of the contact pad exposed by the opening 539 in thepassivation layer 5. The process for forming the patterned circuit layer831 can be referred to as that for forming the patterned circuit layer831 shown in FIG. 10B. The process for forming the polymer layer 99 canbe referred to as that for forming the polymer layer 99 shown in FIG.10B.

Referring to FIG. 10F, a gold wire can be bonded onto a gold layer,platinum layer, palladium layer or ruthenium layer of the patternedcircuit layer 831, exposed by the openings 9939 in the polymer layer 99using a wirebonding process.

As an alternate, referring to FIG. 10F, a nickel layer having athickness between 0.05 and 2 micrometers can be electroless plated onthe contact pad 8310 exposed by the opening 9939 in the polymer layer99, and a gold layer, platinum layer, palladium layer or ruthenium layerhaving a thickness between 0.05 and 2 micrometers can be electrolessplated on the electroless plated nickel layer in the opening 9939 in thepolymer layer 99. Thereafter, a gold wire can be bonded onto theelectroless plated gold layer in the opening 9939 in the polymer layer99 using a wirebonding process.

Referring to FIGS. 10G-10I, a gold wire can be bonded onto a gold layer,platinum layer, palladium layer or ruthenium layer of the patternedcircuit layer 831, exposed by the openings 9939 in the polymer layer 99using a wirebonding process.

As an alternate, referring to FIGS. 10G-10I, a nickel layer having athickness between 0.05 and 2 micrometers can be electroless plated onthe contact pad 8310 exposed by the opening 9939 in the polymer layer99, and a gold layer, platinum layer, palladium layer or ruthenium layerhaving a thickness between 0.05 and 2 micrometers can be electrolessplated on the electroless plated nickel layer in the opening 9939 in thepolymer layer 99. Thereafter, a gold wire can be bonded onto theelectroless plated gold layer in the opening 9939 in the polymer layer99 using a wirebonding process.

The circuitry shown in FIGS. 8B-8F, 9B-9B and 10B-10I can be used in aflash memory chip, in a DRAM memory chip or in a SRAM memory chip. TheI/O pad relocation using the redistribution layer 83 r is particularlyuseful for the stacked packaging with flash, DRAM or SRAM memory chips.The I/O pads of a DRAM chip are usually designed roughly along thecenterline of the chip, and cannot be used for stacked packages. Theredistribution layer 83 r relocates the center pad to the peripheral ofthe chip for the wirebonding in the stacked package. FIGS. 10F and 10Gshow specific examples, with a wire bonded on the relocated pad 8310connected to the original pad 6390 exposed by the opening 539 in thepassivation layer 5 via the thick and wide metal trace of bus 83 r. InFIGS. 8B, 9B, 10B-10G, in an application to a memory chip, an SRAM cell,or a flash memory cell, or a DRAM cell is connected to the input node Xiof the internal circuit 21, such as sense amplifier, internal tri-statebuffer 213 of FIG. 5F, pass circuit 216 of FIG. 5G, latch circuit 217 ofFIG. 5H, circuit of pass circuit 216 and internal driver 212 shown inFIG. 51, or circuit of latch circuit 217 and internal driver 212 shownin FIG. 5J. The various detailed internal circuit 21 and methodsconnecting a memory cell to the internal circuit 21 can be referred toas shown in FIGS. 5F-5J. Referring to FIGS. 8B, 8D-8F, 9B-9D and10B-10I, an SRAM cell, or a flash cell or a DRAM cell is connected toexternal circuit (1) through sense amplifier 214 of FIGS. 5F-5J; (2)through an internal tri-state buffer 213 of FIG. 5F, a pass circuit 216of FIG. 5G, a latch circuit 217 of FIG. 5H, a circuit of a pass circuit216 and an internal driver 212 as shown in FIG. 5I, or a circuit of alatch circuit 217 and an in−+ternal driver 212 as shown in FIG. 5J; (3)through a first fine-line structure formed by stacked vias and metals631; (4) up through a first passivation opening 531; (5) for 10G, alsothrough a first polymer opening 9531; (6) through a fine-line metal 638under the passivation layer 5 for FIG. 10F; while through anover-passivation metal lines, traces or planes 83 in one or more metallayers over the passivation layer 5 for FIG. 10G; (7) for FIG. 10G, downthrough a second polymer opening 9539′; (8) through a second passivationopening 539′; (9) through a fine-line metal structure formed by stackedvias and metal pads 639′, connected to the input of an off-chip I/Ocircuit 42, (10 ) through the output of the off-chip I/O circuit 42connected to an ESD circuit 42, and to a stacked fine-line metal viasand metal pads 639, (11) through an passivation opening 539, (12) for10G, also through a thirdt polymer opening 9539; and (13) through anover-passivation redistribution metal lines or traces or planes 83 r,(14) through over-passivation metal pad 8310 exposed by a polymeropening 9939; (15) through a bonding wire 89′ on the contact pad 8310 ora metal bump 89.

Note that as in FIG. 10G, there may be a polymer layer under or over theredistribution metal layer 83 r. The redistribution metal lines, tracesor planes 83 r can be formed by a (electroplated or electroless plated)gold layer with thickness within a range between 1.5 μm and 30 μm,preferred 2 μm and 10 μm; or by a (electroplated) copper layer withthickness within a range between 2 μm and 100 μm, preferred 3 μm and 20μm, a Ni cap layer (thickness between 0.5 μm and 5 μm) on the copperlayer and an assembly metal layer of Au or Pd, or Ru (thickness between0.05 μm and 5 μm) on the Ni cap layer. A wirebonding is performed on thesurface of the gold, palladium, platinum or ruthenium layer of theover-passivation metal pad 8310.

Referring to FIGS. 8B-8F, 9B-9D, 10B-10E and 10G-10I, the shape of theopenings 531, 532, 534 and 539′ in the passivation layer 5 from a topperspective view may be round, square, rectangular or polygon. If theopenings 531, 532, 534, 539 and 539′ are round, the openings 531, 532,534, 539 and 539′ may have a diameter of between 0.1 and 200 microns,between 1 and 100 microns, or, preferably, between 0.1 and 30 microns.If the openings 531, 532, 534, 539 and 539′ are square, the openings531, 532, 534, 539 and 539′ may have a width of between 0.1 and 200microns, between 1 and 100 microns, or, preferably, between 0.1 and 30microns. If the openings 531, 532, 534, 539 and 539′ are rectangular,the openings 531, 532, 534, 539 and 539′ may have a width of between 0.1and 200 microns, between 1 and 100 microns, or, preferably, between 0.1and 30 microns, and a length of between 1 micron and 1 centimeter. Ifthe openings 531, 532, 534, 539 and 539′ are polygon having more thanfive sides, the openings 531, 532, 534, 539 and 539′ have a greatestdiagonal length of between 0.1 and 200 microns, between 1 and 100microns, or, preferably, between 0.1 and 30 microns. Alternatively, theopenings 531, 532, 534, 539 and 539′ have a greatest transversedimension of between 0.1 and 200 microns, between 1 and 100 microns, or,preferably, between 0.1 and 30 microns. In a case shown in FIGS.10C-10E, 10G, 10H and 10I, the openings 531, 532, 534, 539 and 539′ havea width of between 0.1 and 30 microns, with the lower portion of theopenings 9531, 9532, 9534, 9539 and 9539′ in the polymer layer 95 havinga width of between 20 and 100 microns. The openings 9531, 9532 and 9534in the polymer layer 95 have lower portions having widths or transversedimensions greater than those of the openings 531, 532 and 534 in thepassivation layer 5 aligned with the openings 9531, 9532 and 9534,respectively. The openings 9531, 9532 and 9534 in the polymer layer 95further expose the passivation layer 5 close to the openings 531, 532and 534. The polymer layer 95 covers the peripheral region of thecontact pad exposed by the openings 539 and 539′ in the passivationlayer 5, but the openings 9539 and 9539′ in the polymer layer 95 exposesthe center region of the contact pad exposed by the openings 539 and539′ in the passivation layer 5. The widths or transverse dimensions ofthe openings 539 and 539′ in the passivation layer 5 are greater thanthose of the openings 9539 and 9539′, respectively.

Fourth Embodiment Power/Ground Buses Design Architecture

In the first embodiment of present invention, an external power supplyVdd is provided to a voltage regulator or a voltage converter 41, andthe voltage regulator or a voltage converter 41 output a power supplyVcc to the internal circuits 20. Alternatively, the external powersupply Vdd can be input from an external circuit to the internalcircuits 20, comprising 21, 22, 23 and 24 with an ESD protection circuit44 required to prevent the voltage or current surge from damaging theinternal circuits 20. The ESD circuit 44 is connected in parallel withthe internal circuits 21, 22, 23 and 24. In the first embodiment inFIGS. 1B, 1C, 2B, 2C, 3B, 3C and 3D, an ESD circuit can be also addedand connected in parallel with the voltage regulator or voltageconverter 41, and with the internal circuits 21, 22, 23 and 24. Forexample, the circuit shown in FIG. 1D contains the circuit of FIG. 1C inaddition with an ESD circuit 44. The ESD circuit 44 includes a powernode Dp connected to a thick and wide power bus or plane 81P, deliveringan external power voltage Vdd, and a ground node Dg connected to a thickand wide ground bus or plane 82. The thick and wide power bus or plane81P connects the power node Dp of the ESD circuit 44 and the power nodeof the voltage regulator or converter 41. The thick and wide ground busor plane 82 connects the ground node Dg of the ESD circuit 44 and theground node Rs of the voltage regulator or converter 41. The ESD circuit44 in the circuitry of FIG. 1D may be a reverse biased diode 4333, asshown in FIG. 12E, having an anode connected to the thick and wideground bus or plane 82 and a cathode connected to the thick and widepower bus or plane 81P. An element in FIG. 1D can be referred to as theelement in FIG. 1C indicated by a reference number identical to theelement in FIG. 1D.

FIG. 12B shows a circuitry diagram including a thick and wide power busor plane 81P over the passivation layer 5, connecting an ESD circuit 44and internal circuits 20. FIG. 13B shows a top view realizing thecircuit diagram of FIG. 12B, wherein the bold lines shown in FIG. 13Bmeans a thick and wide metal trace or bus over a passivation layer, andthe fine lines shown in FIG. 13B means a fine metal trace under apassivation layer. FIG. 14B shows a cross-sectional view realizing thecircuit diagram of FIG. 12B. In FIG. 12B, an external power supplyvoltage Vdd is input at a node Ep and distributed to the Vdd nodes,power nodes, Tp, Up, Vp and Wp of the internal circuits 21, 22, 23 and24 through a thick and wide power bus or plane 81P over the passivationlayer 5, through passivation openings 511, 512 and 514, and throughpower fine-line metal traces 611, 612 and 614 under the passivationlayer 5. A power node Dp of an ESD circuit 44 is connected to a thickand wide metal trace, bus or plane 81P, power bus, through a fine-linemetal trace or bus 649, and through an opening 549 in the passivationlayer 5. The thick and wide power bus 81P can be connected to the powernodes Tp, Up, Vp and Wp of the internal circuits 21, 22, 23 and 24 thatmay include a NOR gate, NAND gate, AND gate, OR gate, operationalamplifier, adder, multiplexer, diplexer, multiplier, A/D converter, D/Aconverter, CMOS device, bi-polar CMOS device, bipolar circuit, SRAMcell, DRAM cell, non-volatile memory cell, flash memory cell, EPROMcell, ROM cell, magnetic RAM (MRAM) or sense amplifier. The abovementioned power bus 81P shown in FIG. 12B, over the passivation layer 5,can be connected to the power nodes of the internal circuits 20 or othercircuits in the above-mentioned four embodiments provided with access toa power voltage Vdd. The ESD circuit 44 in the circuitry of FIG. 12B maybe a reverse biased diode 4333, as shown in FIG. 12E, having an anodeconnected to ground and a cathode connected to the thick and wide powerbus or plane 81P.

In FIG. 14B, there is only one patterned circuit layer 811, including aportion serving as the above-mentioned thick and wide metal trace 81P,power bus or plane, over the passivation layer 5. The patterned circuitlayer 811 may contain an adhesion/barrier layer, a seed layer on theadhesion/barrier layer, and an electroplated metal layer 8112 on theseed layer, the adhesion/barrier layer and the seed layer composing thebottom layer 8111.

Referring to FIG. 14B, regards to the process for forming the patternedcircuit layer 811, the adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on asilicon-nitride layer of the passivation layer 5 and on contact pads6490, principally made of aluminum or copper, exposed by multipleopenings 549, 511, 512 and 514 in the passivation layer 5. Thereafter,the seed layer may be formed by sputtering a copper layer having athickness between 200 and 3000 angstroms on the adhesion/barrier layerof any above-mentioned material or by sputtering a gold layer having athickness between 200 and 3000 angstroms on the adhesion/barrier layerof any above-mentioned material. Thereafter, a photoresist layer may beformed on the seed layer, multiple openings in the photoresist layerexposing the seed layer. Thereafter, the metal layer 8112 may be formedby electroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer, by electroplating a copper layerhaving a thickness between 2 and 30 micrometers on the copper layerserving as the seed layer, exposed by the openings in the photoresistlayer and then electroplating a nickel layer having a thickness between0.5 and 10 micrometers on the electroplated copper layer in the openingsin the photoresist layer, by electroplating a copper layer having athickness between 2 and 30 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer,electroplating a nickel layer having a thickness between 0.5 and 10micrometers on the electroplated copper layer in the openings in thephotoresist layer and then electroplating a gold layer, platinum layer,palladium layer or ruthenium layer having a thickness between 0.05 and 2micrometers on the electroplated nickel layer in the openings in thephotoresist layer, or by electroplating a gold layer having a thicknessbetween 2 and 30 micrometers on the gold layer serving as the seedlayer, exposed by the openings in the photoresist layer. Thereafter, thephotoresist layer may be removed. Thereafter, the seed layer not underthe metal layer 8112 is removed using a wet-etching process or using adry-etching process. Thereafter, the adhesion/barrier layer not underthe metal layer 8112 is removed using a wet-etching process or using adry-etching process.

After the patterned circuit layer 811 is formed, a polymer layer 99 canbe formed by spin-on coating a negative photosensitive polyimide layer,such as ester type, on the patterned circuit layer 811 and on thenitride layer of the passivation layer 5, exposing the spin-on coatedphotosensitive polyimide layer, developing the exposed polyimide layerand then curing the developed polyimide layer at the temperature between265 and 285° C. for a time between 30 and 240 minutes in a nitrogen oroxygen-free ambient. Thereby, an opening 9949 may be formed in thepolymer layer 99, exposing a contact pad 8110 of the patterned circuitlayer 811.

Referring to FIG. 14B, for forming a metal bump over the contact pad8110, an adhesion/barrier layer may be formed by sputtering atitanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 99 and on the contact pad 8110 exposed by the opening9949. Thereafter, the seed layer may be formed by sputtering a copperlayer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material. Thereafter, aphotoresist layer may be formed on the seed layer, multiple openings inthe photoresist layer exposing the seed layer. Thereafter, the metalbump may be formed by electroplating a copper layer having a thicknessbetween 0.5 and 10 micrometers on the copper layer serving as the seedlayer, exposed by the openings in the photoresist layer, electroplatinga nickel layer having a thickness between 0.5 and 10 micrometers on theelectroplated copper layer in the openings in the photoresist layer, andthen electroplating a tin-containing layer, such as a tin-lead alloy, atin-silver alloy or a tin-silver-copper alloy, having a thicknessbetween 60 and 200 micrometers on the electroplated nickel layer in theopenings in the photoresist layer. Thereafter, the photoresist layer maybe removed. Thereafter, the seed layer not under the metal bump isremoved using a wet-etching process or using a dry-etching process.Thereafter, the adhesion/barrier layer not under the metal bump isremoved using a wet-etching process or using a dry-etching process.Thereafter, the metal bump can be reflowed to be shaped like a ball fora flip-chip assembly. The metal bump can be connected to a printedcircuit board, ceramic substrate or another semiconductor chip.

Referring to FIG. 14B, for forming another kind of metal bump over thecontact pad 8110, an adhesion/barrier layer may be formed by sputteringa titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, or sputtering a tantalum-containing layer, such as tantalumlayer or tantalum-nitride layer, having a thickness between 1000 and6000 angstroms, on the polymer layer 99 and on the contact pad 8110exposed by the opening 9949. Thereafter, the seed layer may be formed bysputtering a gold layer having a thickness between 200 and 3000angstroms on the adhesion/barrier layer of any above-mentioned material.Thereafter, a photoresist layer may be formed on the seed layer,multiple openings in the photoresist layer exposing the seed layer.Thereafter, the metal bump may be formed by electroplating a gold layerhaving a thickness between 6 and 25 micrometers on the gold layerserving as the seed layer, exposed by the openings in the photoresistlayer. Thereafter, the photoresist layer may be removed. Thereafter, theseed layer not under the metal bump is removed using a wet-etchingprocess or using a dry-etching process. Thereafter, the adhesion/barrierlayer not under the metal bump is removed using a wet-etching process orusing a dry-etching process. The metal bump can be connected to aflexible substrate by a tape-automated bonding (TAB) process, or a glasssubstrate via anisotropic conductive film or paste (ACF or ACP).

Alternatively, referring to FIG. 14B, a nickel layer having a thicknessbetween 0.05 and 2 micrometers can be electroless plated on the contactpad 8110 exposed by the opening 9949, and a gold layer, platinum layer,palladium layer or ruthenium layer having a thickness between 0.05 and 2micrometers can be electroless plated on the electroless plated nickellayer in the opening 9949 in the polymer layer 99. Thereafter, a goldwire can be bonded onto the electroless plated gold layer in the opening9949 in the polymer layer 99 using a wirebonding process.

Alternatively, referring to FIG. 14B, a gold wire can be bonded onto agold layer, platinum layer, palladium layer or ruthenium layer of thepatterned circuit layer 811, exposed by the openings 9949 in the polymerlayer 99 using a wirebonding process.

Referring to FIG. 14D, before the patterned circuit layer 811 is formed,a polymer layer 95 can be optionally formed by spin-on coating anegative photosensitive polyimide layer, such as ester type, on thenitride layer of the passivation layer 5 and on the contact pads 6490,exposing the spin-on coated photosensitive polyimide layer, developingthe exposed polyimide layer and then curing the developed polyimidelayer at the temperature between 265 and 285° C. for a time between 30and 240 minutes in a nitrogen or oxygen-free ambient. Thereby, multipleopenings 9549, 9511, 9512 and 9514 may be formed in the polymer layer95, exposing multiple contact pads 6490 exposed by the openings 549,511, 512 and 514 in the passivation layer 5. After the polymer layer 95is formed, the patterned circuit layer 811 can be formed on the polymerlayer 95 and on the contact pads 6490 exposed by the openings 549, 511,512 and 514. The adhesion/barrier layer of any above-mentioned materialmay be sputtered on the polymer layer 95 and on the contact pads 6490exposed by the openings 9549, 9511, 9512 and 9514 in the polymer layer95.

FIG. 12C shows, in addition to the power Vdd connection in FIG. 12B, aground Vss connection. FIG. 13C shows a top view realizing the circuitdiagram of FIG. 12C, wherein the bold lines shown in FIG. 13C means athick and wide metal trace or bus over a passivation layer, and the finelines shown in FIG. 13C means a fine metal trace under a passivationlayer. FIG. 14C shows a cross-sectional view realizing the circuitdiagram of FIG. 12C. In FIG. 12C, the external ground Vss is input at anode Eg and provided to the Vss nodes Ts, Us, Vs and Ws of the internalcircuits 21, 22, 23 and 24 through a thick and wide metal trace, bus orplane 82, ground bus or plane, over the passivation layer 5, throughopenings 521, 522 and 524 in the passivation layer 5, and throughfine-line metal traces 621, 622 and 624 under the passivation layer 5.The thick and wide ground bus or plane 82 is connected to a Vss node Dgof the ESD circuit 44 through an opening 549′ in the passivation layer 5and through a fine-line ground metal bus 649′ under the passivationlayer 5. The above mentioned power bus 81P shown in FIG. 12C, over thepassivation layer 5, can be connected to the power nodes of the internalcircuits 20 or other circuits in the above-mentioned four embodimentsprovided with access to a power voltage Vdd. The above mentioned groundbus 82 shown in FIG. 12C, over the passivation layer 5, can be connectedto the ground nodes of the internal circuits 20 or other circuits in theabove-mentioned four embodiments provided with access to a groundvoltage Vss. The ESD circuit 44 in the circuitry of FIG. 12C may be areverse biased diode 4333, as shown in FIG. 12E, having an anodeconnected to the thick and wide ground bus or plane 82 and a cathodeconnected to the thick and wide power bus or plane 81P.

Referring to FIG. 14C, there may be multiple patterned circuit layers821 and 812, including the above-mentioned ground bus or plane 82 andthe above-mentioned power bus or plane 81P over the ground bus or plane82, over the passivation layer 5. The process for forming the patternedcircuit layer 821 on the passivation layer 5 and on the contact pads6490′ exposed by the openings 549′, 521, 522 and 524 can be referred toas the process for forming the patterned circuit layer 811 shown in FIG.14B on the passivation layer 5 and on the contact pads 6490 exposed bythe openings 549, 511, 512 and 514. The patterned circuit layer 821 maycontain an adhesion/barrier layer, a seed layer on the adhesion/barrierlayer, and an electroplated metal layer 8212 on the seed layer, theadhesion/barrier layer and the seed layer composing the bottom layer8211. The patterned circuit layer 812 may contain an adhesion/barrierlayer, a seed layer on the adhesion/barrier layer, and an electroplatedmetal layer 8122 on the seed layer, the adhesion/barrier layer and theseed layer composing the bottom layer 8121.

Referring to FIG. 14C, after the patterned circuit layer 821 is formed,a polymer layer 98 can be formed by spin-on coating a negativephotosensitive polyimide layer, such as ester type, on the patternedcircuit layer 821 and on the nitride layer of the passivation layer 5,exposing the spin-on coated photosensitive polyimide layer, developingthe exposed polyimide layer and then curing the developed polyimidelayer at the temperature between 265 and 285° C. for a time between 30and 240 minutes in a nitrogen or oxygen-free ambient. Thereby, anopening 9849′ may be formed in the polymer layer 98, exposing a contactpad of the patterned circuit layer 821.

Referring to FIG. 14C, regards to the process for forming the patternedcircuit layer 812, the adhesion/barrier layer may be formed bysputtering a titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 98 and on the contact pad of the patterned circuit layer821 exposed by the opening 9849′ in the polymer layer 98. Thereafter,the seed layer may be formed by sputtering a copper layer having athickness between 200 and 3000 angstroms on the adhesion/barrier layerof any above-mentioned material or by sputtering a gold layer having athickness between 200 and 3000 angstroms on the adhesion/barrier layerof any above-mentioned material. Thereafter, a photoresist layer may beformed on the seed layer, multiple openings in the photoresist layerexposing the seed layer. Thereafter, the metal layer 8122 may be formedby electroplating a copper layer having a thickness between 2 and 30micrometers on the copper layer serving as the seed layer, exposed bythe openings in the photoresist layer, by electroplating a copper layerhaving a thickness between 2 and 30 micrometers on the copper layerserving as the seed layer, exposed by the openings in the photoresistlayer and then electroplating a nickel layer having a thickness between0.5 and 10 micrometers on the electroplated copper layer in the openingsin the photoresist layer, by electroplating a copper layer having athickness between 2 and 30 micrometers on the copper layer serving asthe seed layer, exposed by the openings in the photoresist layer,electroplating a nickel layer having a thickness between 0.5 and 10micrometers on the electroplated copper layer in the openings in thephotoresist layer and then electroplating a gold layer, platinum layer,palladium layer or ruthenium layer having a thickness between 0.05 and 2micrometers on the electroplated nickel layer in the openings in thephotoresist layer, or by electroplating a gold layer having a thicknessbetween 2 and 30 micrometers on the gold layer serving as the seedlayer, exposed by the openings in the photoresist layer. Thereafter, thephotoresist layer may be removed. Thereafter, the seed layer not underthe metal layer 8122 is removed using a wet-etching process or using adry-etching process. Thereafter, the adhesion/barrier layer not underthe metal layer 8122 is removed using a wet-etching process or using adry-etching process.

After the patterned circuit layer 812 is formed, a polymer layer 99 canbe formed by spin-on coating a negative photosensitive polyimide layer,such as ester type, on the patterned circuit layer 812 and on thepolymer layer 98, exposing the spin-on coated photosensitive polyimidelayer, developing the exposed polyimide layer and then curing thedeveloped polyimide layer at the temperature between 265 and 285° C. fora time between 30 and 240 minutes in a nitrogen or oxygen-free ambient.Thereby, an opening 9949′ may be formed in the polymer layer 99,exposing a contact pad 8120 of the patterned circuit layer 812.

Referring to FIG. 14C, for forming a metal bump over the contact pad8120, an adhesion/barrier layer may be formed by sputtering atitanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, sputtering a chromium-containing layer, such as chromiumlayer, having a thickness between 1000 and 6000 angstroms, or sputteringa tantalum-containing layer, such as tantalum layer or tantalum-nitridelayer, having a thickness between 1000 and 6000 angstroms, on thepolymer layer 99 and on the contact pad 8120 exposed by the opening9949′. Thereafter, the seed layer may be formed by sputtering a copperlayer having a thickness between 200 and 3000 angstroms on theadhesion/barrier layer of any above-mentioned material. Thereafter, aphotoresist layer may be formed on the seed layer, multiple openings inthe photoresist layer exposing the seed layer. Thereafter, the metalbump may be formed by electroplating a copper layer having a thicknessbetween 0.5 and 10 micrometers on the copper layer serving as the seedlayer, exposed by the openings in the photoresist layer, electroplatinga nickel layer having a thickness between 0.5 and 10 micrometers on theelectroplated copper layer in the openings in the photoresist layer, andthen electroplating a tin-containing layer, such as a tin-lead alloy, atin-silver alloy or a tin-silver-copper alloy, having a thicknessbetween 60 and 200 micrometers on the electroplated nickel layer in theopenings in the photoresist layer. Thereafter, the photoresist layer maybe removed. Thereafter, the seed layer not under the metal bump isremoved using a wet-etching process or using a dry-etching process.Thereafter, the adhesion/barrier layer not under the metal bump isremoved using a wet-etching process or using a dry-etching process.Thereafter, the metal bump can be reflowed to be shaped like a ball. Themetal bump can be connected to a printed circuit board, ceramicsubstrate or another semiconductor chip.

Referring to FIG. 14C, for forming another kind of metal bump over thecontact pad 8120, an adhesion/barrier layer may be formed by sputteringa titanium-containing layer, such as titanium layer or atitanium-tungsten-alloy layer, having a thickness between 1000 and 6000angstroms, or sputtering a tantalum-containing layer, such as tantalumlayer or tantalum-nitride layer, having a thickness between 1000 and6000 angstroms, on the polymer layer 99 and on the contact pad 8120exposed by the opening 9949′. Thereafter, the seed layer may be formedby sputtering a gold layer having a thickness between 200 and 3000angstroms on the adhesion/barrier layer of any above-mentioned material.Thereafter, a photoresist layer may be formed on the seed layer,multiple openings in the photoresist layer exposing the seed layer.Thereafter, the metal bump may be formed by electroplating a gold layerhaving a thickness between 6 and 25 micrometers on the gold layerserving as the seed layer, exposed by the openings in the photoresistlayer. Thereafter, the photoresist layer may be removed. Thereafter, theseed layer not under the metal bump is removed using a wet-etchingprocess or using a dry-etching process. Thereafter, the adhesion/barrierlayer not under the metal bump is removed using a wet-etching process orusing a dry-etching process. The metal bump can be connected to aflexible substrate by a tape-automated bonding (TAB) process, or a glasssubstrate via anisotropic conductive film or paste (ACF or ACP).

Alternatively, referring to FIG. 14C, a nickel layer having a thicknessbetween 0.05 and 2 micrometers can be electroless plated on the contactpad 8120 exposed by the opening 9949′ in layer polymer layer 99, and agold layer, platinum layer, palladium layer or ruthenium layer having athickness between 0.05 and 2 micrometers can be electroless plated onthe electroless plated nickel layer in the opening 9949′ in the polymerlayer 99. Thereafter, a gold wire can be bonded onto the electrolessplated gold layer in the opening 9949′ in the polymer layer 99 using awirebonding process.

Alternatively, referring to FIG. 14C, a gold wire can be bonded onto agold layer, platinum layer, palladium layer or ruthenium layer of thepatterned circuit layer 812, exposed by the openings 9949′ in thepolymer layer 99 using a wirebonding process.

Alternatively, before the patterned circuit layer 821 is formed, apolymer layer can be optionally formed by spin-on coating a negativephotosensitive polyimide layer, such as ester type, on the nitride layerof the passivation layer 5 and on the contact pads 6490′, exposing thespin-on coated photosensitive polyimide layer, developing the exposedpolyimide layer and then curing the developed polyimide layer at thetemperature between 265 and 285° C. for a time between 30 and 240minutes in a nitrogen or oxygen-free ambient. Thereby, multiple openingsmay be formed in the polymer layer, exposing multiple contact pads 6490′exposed by the openings 549′, 521, 522 and 524 in the passivation layer5. After the polymer layer is formed, the patterned circuit layer 821can be formed on the polymer layer and on the contact pads 6490′ exposedby the openings 549′, 521, 522 and 524. The adhesion/barrier layer ofany above-mentioned material may be sputtered on the polymer layer andon the contact pads 6490′ exposed by the openings in the polymer layer.

Alternatively, the above-mentioned power bus or plane 81P and theabove-mentioned ground bus or plane 82 can be connected to two ESDcircuits 44 and 45, as shown in FIG. 12D. The above-mentioned power busor plane 81P may connect the power nodes Tp, Up, Vp and Wp of theinternal circuits 21, 22, 23 and 24 and the power nodes Dp and Dp′ ofthe ESD circuits 44 and 45. The above-mentioned ground bus or plane 82may connect the ground nodes Ts, Us, Vs and Ws of the internal circuits21, 22, 23 and 24 and the ground nodes Dg and Dg′ of the ESD circuits 44and 45. The above mentioned power bus 81P shown in FIG. 12D, over thepassivation layer 5, can be connected to the power nodes of the internalcircuits 20 or other circuits in the above-mentioned four embodimentsprovided with access to a power voltage Vdd. The above mentioned groundbus 82 shown in FIG. 12D, over the passivation layer 5, can be connectedto the ground nodes of the internal circuits 20 or other circuits in theabove-mentioned four embodiments provided with access to a groundvoltage Vss. Each of the ESD circuit 44 and 45 in the circuitry of FIG.12D may be a reverse biased diode 4333, as shown in FIG. 12E, having ananode connected to the thick and wide ground bus or plane 82 and acathode connected to the thick and wide power bus or plane 81P.

Referring to FIGS. 12B-12D, 13B, 13C and 14B-14D, the shape of theopenings 511, 512, 514, 521, 522, 524, 549 and 549′ in the passivationlayer 5 from a top perspective view may be round, square, rectangular orpolygon. If the openings 511, 512, 514, 521, 522, 524, 549 and 549′ areround, the openings 511, 512, 514, 521, 522, 524, 549 and 549′ may havea diameter of between 0.1 and 200 microns, between 1 and 100 microns,or, preferably, between 0.1 and 30 microns. If the openings 511, 512,514, 521, 522, 524, 549 and 549′ are square, the openings 511, 512, 514,521, 522, 524, 549 and 549′ may have a width of between 0.1 and 200microns, between 1 and 100 microns, or, preferably, between 0.1 and 30microns. If the openings 511, 512, 514, 521, 522, 524, 549 and 549′ arerectangular, the openings 511, 512, 514, 521, 522, 524, 549 and 549′ mayhave a width of between 0.1 and 200 microns, between 1 and 100 microns,or, preferably, between 0.1 and 30 microns, and a length of between 1micron and 1 centimeter. If the openings 511, 512, 514, 521, 522, 524,549 and 549′ are polygon having more than five sides, the openings 511,512, 514, 521, 522, 524, 549 and 549′ have a greatest diagonal length ofbetween 0.1 and 200 microns, between 1 and 100 microns, or, preferably,between 0.1 and 30 microns. Alternatively, the openings 511, 512, 514,521, 522, 524, 549 and 549′ have a greatest transverse dimension ofbetween 0.1 and 200 microns, between 1 and 100 microns, or, preferably,between 0.1 and 30 microns. In a case shown in FIG. 14D, the openings511, 512, 514 and 549 have a width of between 0.1 and 30 microns, withthe lower portion of the openings 9511, 9512, 9514 and 9549 in thepolymer layer 95 having a width of between 20 and 100 microns. Theopenings 9511, 9512 and 9514 in the polymer layer 95 have lower portionshaving widths or transverse dimensions greater than those of theopenings 511, 512 and 514 in the passivation layer 5 aligned with theopenings 9511, 9512 and 9514, respectively. The openings 9511, 9512 and9514 in the polymer layer 95 further expose the passivation layer 5close to the openings 511, 512 and 514. The polymer layer 95 covers theperipheral region of the contact pad exposed by the opening 549 in thepassivation layer 5, but the opening 9549 in the polymer layer 95exposes the center region of the contact pad exposed by the openings 549in the passivation layer 5. The width or transverse dimension of theopening 549 in the passivation layer 5 is greater than that of theopening 9549.

Methods and Specification of forming the over-passivation Scheme

The main characteristics of the over-passivation schemes in all (thefirst, second, third and fourth embodiment) embodiments of thisinvention are: thick metal layers each having a thickness of between 2and 200 micrometers, and preferably of between 2 and 30 micrometers, andthick dielectric layers each having a thickness of between 2 and 3000micrometers, and preferably of between 2 and 30 micrometers. FIGS.15C-15K show an embossing process to fabricate one or more patternedcircuit layers 801 and/or 802 over the passivation layer 5 described inall embodiments in this invention. FIGS. 15C-15G and FIGS. 16A-16L showa double embossing process to fabricate one or more patterned circuitlayers 801 and 802 over the passivation layer 5 described in allembodiments in this invention. In the embossing as shown in FIGS.15C-15K, a polymer layer 95, 98 or 99 may be provided under thepatterned circuit layer 801, between the patterned circuit layers 801and 802 or over the patterned circuit layer 802. In the double embossingas shown in FIGS. 15C-15G and FIGS. 16A-16L, a polymer layer 95, 98 or99 may be provided under the patterned circuit layer 801, between thepatterned circuit layers 801 and 802 or over the patterned circuit layer802. FIGS. 15A-15L and FIGS. 16A-16L are based on the structure of FIG.10E in the third embodiment, and are used as examples to illustratemethods for forming the over-passivation scheme for all embodiments inthis invention. In other words, the methods described and thespecification specified in the following paragraphs can be applied toall thick and wide metal traces, buses or planes 81, 81P, 82, 83, 83′ or85 in the above-mentioned embodiments of this invention.

The over-passivation process begins when the conventional IC waferprocess ends. FIG. 15A shows a starting material for theover-passivation process. The over-passivaion process starts on a chip10 in a finished conventional IC wafer fabricated in a conventional ICfab.

The conventional finished IC chip 10 comprises elements, as follows:

Reference number of 1 indicates a substrate, usually a siliconsubstrate. The silicon substrate can be an intrinsic, a p-type, or ann-type silicon substrate. For a high performance chip, a SiGe orSilicon-On-Insulator (SOI) substrate can be used. A SiGe substratecomprises an epitaxial layer on the surface of a silicon substrate. AnSOI substrate comprises an insulating layer (preferred silicon oxide) ona silicon substrate, and a Si or SiGe epitaxial layer formed over theinsulating layer.

Reference number of 2 indicates a device layer, usually a semiconductordevice, in and/or on the substrate 1. The semiconductor device comprisesan MOS transistor 2′, either an n-MOS or a p-MOS transistor. The MOStransistor comprises a gate (usually a poly-silicon, a tungstenpoylcide, a tungsten silicide, titanium silicide, cobalt silicide, or asalicide gate), a source, and a drain. Other devices are bipolartransistors, DMOS (Diffused MOS), LDMOS (Lateral Diffused MOS), CCD(Charged-Coupled Device), CMOS sensors, photo-sensitive diodes,resistors (formed by the polysilicon layer or the diffusion area in thesilicon substrate). The devices form various circuits, such as CMOScircuits, NMOS circuits, PMOS circuits, BiCMOS circuits, CMOS sensorcircuits, DMOS power circuits, LDMOS circuits. The layer comprises theinternal circuits 20 (comprising 21, 22, 23 and 24) in all embodiments;the regulator or voltage converter 41 in the first embodiment; theoff-chip circuits 40 (comprising 42 and 43) in the third embodiment, andthe ESD circuit 44 in the fourth embodiment.

Reference number of 6 indicates a fine-line scheme, comprising fine-linemetal layers 60 and fine-line via plugs 60′ in vias 30′ of fine-linedielectric layers 30. The fine-line scheme 6 comprises fine line metalsin all embodiments of this invention: (1) 611, 612, 614, 619, 619′, 621,622, 624 and 629 of the first embodiment; (2) 631, 632 and 634 of thesecond embodiment; (3) 631, 632, 634, 639, 639′, 6391, 6391′, 6311, 6321and 6341 of the third embodiment; (4) 611, 612, 614, 649, 621, 622, 624and 649′ of the fourth embodiment. The fine-line metal layers 60 can bealuminum or copper layers, or more specifically, sputtered aluminumlayers or damascene copper layers. The fine-line metal scheme 6 can be(1) all fine-line metal layers 60 are aluminum layers, (2) all fine-linemetal layers 60 are copper layers, (3) the bottom layers are aluminumlayers and the top layers are copper layer, (4) the bottom layers arecopper layers and the top layers are aluminum layers. Each of thefine-line metal layers 60 has thickness between 0.05 and 2 micrometers,preferred between 0.2 and 1 μm, with horizontal design rules (the width)of lines or traces between 20 nanometers and 15 micrometers, preferred20 nanometers and 2 micrometers. The aluminum layer is usually formed bya physical vapor deposition (PVD) method, such as the sputtering method,and then patterned by depositing a photoresist layer with thicknessbetween 0.1 and 4 μm, preferred 0.3 and 2 μm, followed by a wet or dryetching, preferred dry plasma etch (usually containing fluorine plasma).As an option, an adhesion/barrier (Ti, TiW, TiN or a composit layer ofabove metals) may be added under the aluminum layer, and/or ananti-reflection layer (TiN) may be also added over the aluminum layer.The vias 30′ are optionally filled with blanketed CVD tungstendeposition, followed by a chemical mechanical polishing (CMP) of thetungsten metal layer to form via plugs 60′. The copper layer is usuallyformed by electroplating method and damascene process as follows: (1)depositing a copper diffusion barrier layer (such as oxynitride ornitride layer of thickness between 0.05 and 0.25 μm); (2) depositing adielectric layer 30 of a thickness between 0.1 and 2.5 μm, preferredbetween 0.3 and 1.5 μm by PECVD, spin-on coating, and/or High-DensityPlasma (HDP) CVD methods; (3) patterning the dielectric layer 30 bydepositing a photoresist layer with a thickness of between 0.1 and 4 μm,and preferably of between 0.3 and 2 μm, then exposing and developing thephotoresist layer to form openings and/or trenches, and then strippingthe photoresist layer; (4) depositing an adhesion/barrier layer and anelectroplating seed layer by sputtering and/or CVD methods. Theadhesion/barrier layer comprises Ta, TaN, TiN, Ti or TiW or a compositelayer formed by above materials. The electroplating seed layer, formedon the adhesion/barrier layer, is usually a copper layer formed bysputtering Cu or CVD copper or a CVD Cu followed by a sputtering Cu; (5)electroplating a copper layer over the electroplating seed layer to athickness between 0.05 and 2 μm, preferred between 0.2 and 1 μm; (6)removing the electroplated copper layer, the electroplating seed layerand the adhesion/barrier layer not in the openings or trenches of thedielectric layer 30 by polishing (preferred chemical mechanicalpolishing, CMP) the wafer until the dielectric layer underlying theadhesion/barrier layer exposed. Only the metals in the openings ortrenches remain after CMP; and the remained metals are used as metalconductors (lines, traces and/or planes) or via plugs 60′ connecting twoadjacent metal layers 60. As another alternative, a double-damasceneprocess is used to form metal via plugs and metal traces, lines, orplanes simultaneously with one electroplating process, one CMP process.Two photolithography processes, and two dielectric depositing processesare applied in the double-damascene process. The double-damasceneprocess adds more process steps of deposing and patterning another layerof dielectrics between step (3) of patterning a dielectric layer andstep (4) of depositing the metal layer in the above single damasceneprocess. The dielectric layer 30 is formed by CVD (Chemical VaporDeposition), PECVD (Plasma-Enhanced CVD), High-Density-Plasma (HDP) CVD,or a spin-on method. The materials of dielctric layers 30 compriselayers of silicon oxide, silicon nitride, silicon oxynitride, PECVDTEOS, Spin-On Glass (SOG, silicate-based or siloxane-based), FluorinatedSilicate Glass (FSG), or a low-K dielectric material such as BlackDiamond (generated by machines of Applied Materials, Inc.), or ULK CORAL(generated by machines of Novellus Inc.), or SiLK (of IBM Corp.) low kdielectrics. The PECVD silicon oxide or PECVD TEOS or HDP oxide has adielectric constant K between 3.5 and 4.5; the PECVD FSG or HDP FSG hasa K value between 3.0 and 3.5, and the low K dielectric material has a Kvalue between 1.5 and 3.0. The low K dielectric material, such as BlackDiamond, is porous, and comprises hydrogen and carbon in addition tosilicon and oxygen, the formula is H_(w)C_(x)Si_(Y)O_(z). The fine-linedielectric layers 30 usually comprise inorganic materials, which is toachieve a thicker than 2 μm layer. Each of the dielectric layers 30 hasa thickness between 0.05 and 2 μm. The vias 30′ in the dielectric layer30 is formed by wet and/or dry etching with photoresist patterning,preferred dry etching. The dry etch species comprise fluorine plasma.

Reference number of 5 indicates a passivation layer. The passivationlayer 5 plays a very important role in this invention. The passivationlayer 5 has been a major element in the IC industry. As described in“Silicon Processing in the VLSI era” Volume 2, by S. Wolf, published byLattice Press, 1990, the passivation layer 5 is used to be defined asthe final layer in the conventional IC process, and is deposited overthe entire top surface of the wafer. The passivation layer 5 is aninsulating, protective layer that prevents mechanical and chemicaldamage during assembly and packaging. In addition to preventingmechanical scratch, it prevents the penetration of mobile ions, such assodium, and transition metal, such as gold, copper, into the underlyingIC devices. It also protects the underlying devices and interconnection(metals and dielectrics) from moisture penetration or othercontainments. The passivation layer 5 usually comprises asilicon-nitride layer with a thickness of between 0.2 and 1.5 μm, andpreferably of between 0.3 and 1.0 μm, and/or a silicon-oxynitride layerwith a thickness of between 0.2 and 1.5 μm, and preferably of between0.3 and 1.0 μm. Other materials used in the passivation layer 5 arePECVD silicon oxide, PETEOS oxide, phosphosilicate glass (PSG),borophosphos silicate glass (BPSG), high-density plasma (HDP) oxide.

For example, the passivation layer 5 may be formed by depositing anoxide layer with a thickness of between 0.1 and 1 μm, and preferably ofbetween 0.3 and 0.7 μm, and then depositing a nitride layer with athickness of between 0.25 and 1.2 μm, and preferably of between 0.35 and1 μm, on the oxide layer, wherein the oxide layer can be PECVD siliconoxide, PETEOS oxide or high-density plasma (HDP) oxide. This type of thepassivation layer 5 is usually used for the case when the metalinterconnection under the passivation layer 5 is formed by a processincluding an aluminum sputtering process and an aluminum etchingprocess.

Alternatively, the passivation layer 5 may be formed by depositing anoxynitride layer with a thickness of between 0.05 and 0.35 μm, andpreferably of between 0.1 and 0.2 μm, next depositing a first oxidelayer with a thickness of 0.2 and 1.2 μm, and preferably of between 0.3and 0.6 μm, on the oxynitride layer, next depositing a nitride layerwith a thickness of between 0.2 and 1.2 μm, and preferably of between0.3 and 0.5 μm, on the first oxide layer, and then depositing a secondoxide layer with a thickness of between 0.2 and 1.2 μm, and preferablyof between 0.3 and 0.6 μm, on the nitride layer, wherein the first andsecond oxide layers can be PECVD silicon oxide, PETEOS oxide orhigh-density plasma (HDP) oxide. This type of passivation layer 5 isusually used for the case when the metal interconnection under thepassivation layer 5 is formed by a process including a copperelectroplating process, a chemical mechanical polishing (CMP) process,and a copper damascene process.

The above description and specification for the substrate 1, the devicelayer 2, the fine-line metal scheme 6, the dielectric layer 30 and thepassivation layer 5 can be applied to the first, second, third andfourth embodiments of this invention.

Openings 50 are formed in the passivation layer 5 by wet and/or dryetching, preferred dry etching. The specification of the openings 50 andthe process of forming the same can be applied to (1) openings 511, 512,514, 519, 519′, 521, 522, 524 and 529 in the first embodiment; (2)openings 531, 532, 534, 531′, 532′ and 534′ in the second embodiment;(3) openings 531, 532, 534, 539 and 539′ in the third embodiment; (4)openings 511, 512, 514, 549, 549′, 521, 522, 524, 559 and 559′ in thefourth embodiment. The width of the passivation opening 50 can bebetween 0.1 and 200 micrometers, between 1 and 100 μm or between 0.5 and30 μm. The shape of the opening 50 from a top view may be a circle, andthe diameter of the circle-shaped opening 50 may be between 0.1 and 30μm or between 30 and 200 μm. Alternatively, the shape of the opening 50from a top view may be a square, and the width of the square-shapedopening 50 may be between 0.1 and 30 μm or between 30 and 200 μm.Alternatively, the shape of the opening 50 from a top view may be apolygon, such as hexagon or octagon, and the polygon-shaped opening 50may have a width of between 0.1 and 30 μm or between 30 and 200 μm.Alternatively, the shape of the opening 50 from a top view may be arectangle, and the rectangle-shaped opening 50 may have a shorter widthof between 0.1 and 30 μm or between 30 and 200 μm. The width of theopenings 531, 532, 534, 531′, 532′, 534′, 511, 512 and 514 in thepassivation layer 5 for the internal circuits 20 (comprising 21, 22, 23and 24) is between 0.1 and 100 μm, preferred between 0.1 and 30 μm. Thepassivation openings 519, 519′ and 529 for the voltage regulator orvoltage converter 41, the passivation openings 539 and 539′ for theoff-chip circuits 42 and 43, or the passivation openings 549, 549′, 559and 559′ for the ESD circuit 44 may have a width greater than those ofthe openings 531, 532, 534, 511, 512 and 514, in a range between 1 and150 μm, preferred between 5 and 100 μm. Alternatively, the passivationopenings 519, 519′ and 529 for the voltage regulator or voltageconverter 41, the passivation openings 539 and 539′ for the off-chipcircuits 42 and 43, or the passivation openings 549, 549′, 559 and 559′for the ESD circuit 44 may have a width greater than those of theopenings 531, 532 and 534, in a range between 0.1 and 30 μm. Thepassivation openings 50 expose metal pads of the top-most layer offine-line metal layers 60 for electrical contacts of theover-passivation metals.

The finished conventional chip 10 on a silicon wafer is fabricated usingdifferent generations of IC process technologies, such as 1 μm, 0.8 μm,0.6 μm, 0.5 μm, 0.35 μm, 0.25 μm, 0.18 μm, 0.25 μm, 0.13 μm, 90 nm, 65nm, 45 nm, 35 nm, 25 nm technologies, defined by the gate length oreffective channel length of the MOS transistors 2′. The IC chip 10 onthe silicon wafer is processed using photolithography process. Thephotolithography process comprises coating, exposing and developing thephotoresist. The photoresist used to process the chip 10 has a thicknessof between 0.1 and 4 μm. A 5 × stepper or a scanner exposes thephoresist. The 5 × means that the dimension on a photo mask (usual madeof quartz) is reduced on the wafer when light beam is projected from thephoto mask onto the wafer, and the dimension of a feature on the photomask is 5 times of the dimension on the wafer. The scanner is used inadvanced generations of IC process technologies, and is usually with 4 ×dimension reduction to improve the resolution. The wavelength of thelight beam used in the stepper or the scanner is 436 nm (g-line), 365 nm(i-line), 248 nm (Deep Ultraviolet, DUV), 193 nm (DUV), or 157 nm (DUV),or 13.5 nm (Extreme UV, EUV). The high-index immersion photolithographyis also used to achieve fine-line features in the IC chip 10.

The conventional IC chip 10 in the silicon wafer is processed in a cleanroom with Class 10 or better, for example Class 1. A Class 10 clean roomallows maximum number of particles per cubic foot: 1 larger than 1 μm,10 larger than 0.5 μm, 30 larger than 0.3 μm, 75 larger than 0.2 μm, 350larger than 0.1 μm, while a Class 1 clean room allows maximum number ofparticles per cubic foot: 1 larger than 0.5 μm, 3 larger than 0.3 μm, 7larger than 0.2 μm, 35 larger than 0.1 μm.

When copper is used as the fine-line metal layers 60, and exposed by theopenings 50 in the passivation layer 5, a metal cap 66, comprising 661,662, 664, 669 and 669′, is used to protect the exposed copper pad fromcorrosion, and also can be used for wirebonding in the conventional ICchip 10, as shown in FIG. 15B. The metal cap 66 having a thickness ofbetween 0.4 and 3 μm comprises an aluminum-containing layer (such asaluminum layer, aluminum-copper alloy layer or Al—Si—Cu alloy layer), agold layer, a Ti layer, a TiW layer, a Ta layer, a TaN layer, or a Nilayer. If the metal cap 66 is an aluminum-containing layer (such asaluminum layer, aluminum-copper alloy layer or Al—Si—Cu alloy layer), abarrier layer having a thickness of between 0.01 and 0.7 μm is formedbetween the copper pad and the aluminum cap 66, and the barrier layercomprises Ti, TiW, TiN, Ta, TaN, Cr or Ni. For example, a barrier layerhaving a thickness of between 0.01 and 0.7 μm can be formed on thecopper pad exposed by the opening 50, and an aluminum-containing layerhaving a thickness of between 0.4 and 3 μm is formed on the barrierlayer, wherein the barrier layer may be made of titanium, atitanium-tungsten alloy, titanium nitride, tantalum, tantalum nitride,chromium or alloy of refractory metal, and the aluminum-containing layermay be an aluminum layer, an aluminum-copper alloy layer or an Al—Si—Cualloy layer. The IC chip 10 with metal caps 66 can be used as options inall embodiments in this invention.

FIGS. 15C-15K show process steps of fabricating an over-passivationscheme 8 over the conventional IC chip 10 shown in FIG. 15A or FIG. 15B.The process steps shown in FIGS. 15C-15K are used to form the structureshown in FIG. 10E, for example, with two layers of over-passivationmetals, and with a complete design architecture for interconnecting theinternal circuits 20 and off-chip circuits 40. This example shows twoover-passivation metal layers, while one metal layer, three metallayers, four metal layers or more metal layers over the passivationlayer 5 can be formed using the same or similar methods, and the same orsimilar specification described in FIGS. 15C-15K. In other words, thefollowing description and specification apply to all embodiments in thisinvention.

Refer to FIG. 15K now, an over-passivation scheme 8 is formed over astarting material, which is a chip 10 (described in FIG. 15A or FIG.15B) fabricated in a conventional IC fab. The over-passivation scheme 8comprises over-passivation metals 80 and over-passivation polymers orinsulators 90. The over-passivation metals 80 comprise one, two, three,four or more metal layers. In the example of comprising two metallayers, the over-passivation metals 80 comprise a first metal layer 801and a second metal layer 802. The specification of the first metal layer801 and the process of forming the same can be applied to (1) 811 and821 in the first embodiment; (2) 831 in the second embodiment; (3) 831in the third embodiment; (4) 811 and 821 in the fourth embodiment. Thespecification of the second metal layer 802 and the process of formingthe same can be applied to (1) 812 in the first embodiment; (2) 832 inthe second embodiment; (3) 832 in the third embodiment; (4) 812 in thefourth embodiment.

The metals used in the over-passivation metal layers 80 are mainlycopper, gold, silver, palladium, rhodium, platinum, ruthenium, andnickel. The metal line, trace, or plane in the over-passivation metalscheme 80 usually comprises composite layers of metals in a stack. Thecross-section in FIG. 15K show two composite layers 8001 and 8002 ineach of the over-passivation metal layers 80, which can be applied to asthe two composite layers 8111 and 8112 of the patterned circuit layer811, respectively, in FIGS. 3B, 14B and 14D, as the two composite layers8211 and 8212 of the patterned circuit layer 821, respectively, in FIGS.3C and 14C, as the two composite layers 8121 and 8122 of the patternedcircuit layer 812, respectively, in FIGS. 3C and 14C, as the twocomposite layers 8311 and 8312 of the patterned circuit layer 831,respectively, in FIGS. 7B, 7C, 7D, 10B, 10C, 10D, 10E, 10F, 10G, 10H and10I, and as the two composite layers 8321 and 8322 of the patternedcircuit layer 832, respectively, in FIGS. 7C, 10C and 10E. The bottomlayer of each over-passivation metal layers 80 is anadhesion/barrier/seed layer 8001 (comprising 8011 and 8021), comprisingan adhesion/barrier layer (not shown) and a seed layer (not shown) onthe adhesion/barrier layer. The specification of theadhesion/barrier/seed layers 8001 (comprising 8011 and 8021) and theprocess of forming the same can be applied to (1) adhesion/barrier/seedlayers 8111, 8121 and 8211 in the first embodiment; (2)adhesion/barrier/seed layers 8311 and 8321 in the second embodiment; (3)adhesion/barrier/seed layers 8311 and 8321 in the third embodiment; (4)adhesion/barrier/seed layers 8111, 8211 and 8121 in the fourthembodiment. The top layer of each over-passivation metal layers 80 is aconduction bulk metal layer 8002, comprising 8012 and 8022. Thespecification of the conduction bulk metal layers 8002 (comprising 8012and 8022) and the process of forming the same can be applied to (1)conduction bulk metal layers 8112, 8122 and 8212 in the firstembodiment; (2) conduction bulk metal layers 8312 and 8322 in the secondembodiment; (3) conduction bulk metal layers 8312 and 8322 in the thirdembodiment; (4) conduction bulk metal layers 8112, 8212 and 8122 in thefourth embodiment.

The material of the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8001 can be Ti (titanium), W, Co, Ni, TiN(titanium nitride), TiW (titanium-tungsten alloy), V, Cr (chromium), Cu,CrCu, Ta (tantalum), TaN (tantalum nitride), or alloy or composite layerof above materials. The adhesion/barrier layer can be formed byelectroplating, electroless plating, chemical vapor deposition (CVD), orPVD (such as sputtering or evaporation), preferred deposited by PVD(physical vapour deposition) such as metal sputtering process. Thethickness of the adhesion/barrier layer is between 0.02 and 0.8 μm,preferred between 0.05 and 0.5 μm.

For example, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering a titaniumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, on a polymer layer 95 and on pads, principallymade of aluminum, exposed by openings 950 in the polymer layer 95.Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering atitanium-tungsten-alloy layer with a thickness of between 0.02 and 0.81μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer 95and on the pads, principally made of aluminum, exposed by the openings950 in the polymer layer 95. Alternatively, the adhesion/barrier layerat the bottom of the adhesion/barrier/seed layer 8011 may be formed bysputtering a titanium-nitride layer with a thickness of between 0.02 and0.8 μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer95 and on the pads, principally made of aluminum, exposed by theopenings 950 in the polymer layer 95. Alternatively, theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8011 may be formed by sputtering a chromium layer with a thickness ofbetween 0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, onthe polymer layer 95 and on the pads, principally made of aluminum,exposed by the openings 950 in the polymer layer 95. Alternatively, theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8011 may be formed by sputtering a tantalum-nitride layer with athickness of between 0.02 and 0.81 μm, and preferably of between 0.05and 0.5 μm, on the polymer layer 95 and on the pads, principally made ofaluminum, exposed by the openings 950 in the polymer layer 95.Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering a tantalumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, on the polymer layer 95 and on the pads,principally made of aluminum, exposed by the openings 950 in the polymerlayer 95.

For example, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering a titaniumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, on the polymer layer 95 and on the pads,principally made of copper, exposed by the openings 950 in the polymerlayer 95. Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering atitanium-tungsten-alloy layer with a thickness of between 0.02 and 0.8μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer 95and on the pads, principally made of copper, exposed by the openings 950in the polymer layer 95. Alternatively, the adhesion/barrier layer atthe bottom of the adhesion/barrier/seed layer 8011 may be formed bysputtering a titanium-nitride layer with a thickness of between 0.02 and0.8 μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer95 and on the pads, principally made of copper, exposed by the openings950 in the polymer layer 95. Alternatively, the adhesion/barrier layerat the bottom of the adhesion/barrier/seed layer 8011 may be formed bysputtering a chromium layer with a thickness of between 0.02 and 0.81μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer 95and on the pads, principally made of copper, exposed by the openings 950in the polymer layer 95. Alternatively, the adhesion/barrier layer atthe bottom of the adhesion/barrier/seed layer 8011 may be formed bysputtering a tantalum-nitride layer with a thickness of between 0.02 and0.8 μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer95 and on the pads, principally made of copper, exposed by the openings950 in the polymer layer 95. Alternatively, the adhesion/barrier layerat the bottom of the adhesion/barrier/seed layer 8011 may be formed bysputtering a tantalum layer with a thickness of between 0.02 and 0.81μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer 95and on the pads, principally made of copper, exposed by the openings 950in the polymer layer 95.

For example, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering a titaniumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, on the polymer layer 95 and on thealuminum-containing layer (such as aluminum layer, aluminum-copper alloylayer or Al—Si—Cu alloy layer), exposed by the openings 950 in thepolymer layer 95, of the metal caps 66 over the copper pads.Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering atitanium-tungsten-alloy layer with a thickness of between 0.02 and 0.8μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer 95and on the aluminum-containing layer (such as aluminum layer,aluminum-copper alloy layer or Al—Si—Cu alloy layer) of the metal caps66, exposed by the openings 950 in the polymer layer 95, over the copperpads. Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering atitanium-nitride layer with a thickness of between 0.02 and 0.8 μm, andpreferably of between 0.05 and 0.5 μm, on the polymer layer 95 and onthe aluminum-containing layer (such as aluminum layer, aluminum-copperalloy layer or Al—Si—Cu alloy layer), exposed by the openings 950 in thepolymer layer 95, of the metal caps 66 over the copper pads.Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering a chromiumlayer with a thickness of between 0.02 and 0.81 μm, and preferably ofbetween 0.05 and 0.5 μm, on the polymer layer 95 and on thealuminum-containing layer (such as aluminum layer, aluminum-copper alloylayer or Al—Si—Cu alloy layer) of the metal caps 66, exposed by theopenings 950 in the polymer layer 95, over the copper pads.Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering atantalum-nitride layer with a thickness of between 0.02 and 0.8 μm, andpreferably of between 0.05 and 0.5 μm, on the polymer layer 95 and onthe aluminum-containing layer (such as aluminum layer, aluminum-copperalloy layer or Al—Si—Cu alloy layer), exposed by the openings 950 in thepolymer layer 95, of the metal caps 66 over the copper pads.Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8011 may be formed by sputtering a tantalumlayer with a thickness of between 0.02 and 0.81 μm, and preferably ofbetween 0.05 and 0.5 μm, on the polymer layer 95 and on thealuminum-containing layer (such as aluminum layer, aluminum-copper alloylayer or Al—Si—Cu alloy layer) of the metal caps 66, exposed by theopenings 950 in the polymer layer 95, over the copper pads.

For example, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8021 may be formed by sputtering a titaniumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, on a polymer layer 98 and on a gold layer ofthe conduction bulk layer 8012 exposed by openings 980 in the polymerlayer 98. Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8021 may be formed by sputtering atitanium-tungsten-alloy layer with a thickness of between 0.02 and 0.8μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer 98and on the gold layer of the conduction bulk layer 8012 exposed by theopenings 980 in the polymer layer 98. Alternatively, theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8021 may be formed by sputtering a titanium-nitride layer with athickness of between 0.02 and 0.8 μm, and preferably of between 0.05 and0.5 μm, on the polymer layer 98 and on the gold layer of the conductionbulk layer 8012 exposed by the openings 980 in the polymer layer 98.Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8021 may be formed by sputtering a chromiumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, on the polymer layer 98 and on the gold layerof the conduction bulk layer 8012 exposed by the openings 980 in thepolymer layer 98. Alternatively, the adhesion/barrier layer at thebottom of the adhesion/barrier/seed layer 8021 may be formed bysputtering a tantalum-nitride layer with a thickness of between 0.02 and0.8 μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer98 and on the gold layer of the conduction bulk layer 8012 exposed bythe openings 980 in the polymer layer 98. Alternatively, theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8021 may be formed by sputtering a tantalum layer with a thickness ofbetween 0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, onthe polymer layer 98 and on the gold layer of the conduction bulk layer8012 exposed by the openings 980 in the polymer layer 98.

For example, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8021 may be formed by sputtering a titaniumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, on a polymer layer 98 and on a copper layer ofthe conduction bulk layer 8012 exposed by multiple openings 980 in thepolymer layer 98. Alternatively, the adhesion/barrier layer at thebottom of the adhesion/barrier/seed layer 8021 may be formed bysputtering a titanium-tungsten-alloy layer with a thickness of between0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, on thepolymer layer 98 and on the copper layer of the conduction bulk layer8012 exposed by the openings 980 in the polymer layer 98. Alternatively,the adhesion/barrier layer at the bottom of the adhesion/barrier/seedlayer 8021 may be formed by sputtering a titanium-nitride layer with athickness of between 0.02 and 0.8 μm, and preferably of between 0.05 and0.5 μm, on the polymer layer 98 and on the copper layer of theconduction bulk layer 8012 exposed by the openings 980 in the polymerlayer 98. Alternatively, the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8021 may be formed by sputtering a chromiumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, on the polymer layer 98 and on the copper layerof the conduction bulk layer 8012 exposed by the openings 980 in thepolymer layer 98. Alternatively, the adhesion/barrier layer at thebottom of the adhesion/barrier/seed layer 8021 may be formed bysputtering a tantalum-nitride layer with a thickness of between 0.02 and0.8 μm, and preferably of between 0.05 and 0.5 μm, on the polymer layer98 and on the copper layer of the conduction bulk layer 8012 exposed bythe openings 980 in the polymer layer 98. Alternatively, theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8021 may be formed by sputtering a tantalum layer with a thickness ofbetween 0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, onthe polymer layer 98 and on the copper layer of the conduction bulklayer 8012 exposed by the openings 980 in the polymer layer 98.

The seed layer at the top of the adhesion/barrier/seed layer 8001, forthe subsequent electroplating process, usually formed by electroplating,electroless, CVD, or PVD (such as sputtering), preferred deposited byPVD such as metal sputtering process. The material used for the seedlayer, usually made of the same metal material as the conduction bulkmetal formed in the subsequent electroplating process, can be Au, Cu,Ag, Ni, Pd, Rh, Pt or Ru. The material of the seed layer varies with thematerial of the electroplated metal layer formed on the seed layer. Whena gold layer is to be electroplated on the seed layer, gold is apreferable material to the seed layer. When a copper layer is to beelectroplated on the seed layer, copper is a preferable material to theseed layer. The thickness of the electroplating seed layer is between0.05 and 1.2 μm, preferred between 0.05 and 0.8 μm.

For example, when the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8001 is formed by sputtering a titaniumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, the seed layer at the top of theadhesion/barrier/seed layer 8001 can be formed by sputtering a goldlayer with a thickness of between 0.05 and 1.2 μm, and preferably ofbetween 0.05 and 0.8 μm, on the titanium layer. When theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8001 is formed by sputtering a titanium-tungsten-alloy layer with athickness of between 0.02 and 0.8 μm, and preferably of between 0.05 and0.5 μm, the seed layer at the top of the adhesion/barrier/seed layer8001 can be formed by sputtering a gold layer with a thickness ofbetween 0.05 and 1.2 μm, and preferably of between 0.05 and 0.8 μm, onthe titanium-tungsten-alloy layer. When the adhesion/barrier layer atthe bottom of the adhesion/barrier/seed layer 8001 is formed bysputtering a titanium-nitride layer with a thickness of between 0.02 and0.8 μm, and preferably of between 0.05 and 0.5 μm, the seed layer at thetop of the adhesion/barrier/seed layer 8001 can be formed by sputteringa gold layer with a thickness of between 0.05 and 1.2 μm, and preferablyof between 0.05 and 0.8 μm, on the titanium-nitride layer. When theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8001 is formed by sputtering a chromium layer with a thickness ofbetween 0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, theseed layer at the top of the adhesion/barrier/seed layer 8001 can beformed by sputtering a gold layer with a thickness of between 0.05 and1.2 μm, and preferably of between 0.05 and 0.8 μm, on the chromiumlayer. When the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8001 is formed by sputtering atantalum-nitride layer with a thickness of between 0.02 and 0.8 μm, andpreferably of between 0.05 and 0.5 μm, the seed layer at the top of theadhesion/barrier/seed layer 8001 can be formed by sputtering a goldlayer with a thickness of between 0.05 and 1.2 μm, and preferably ofbetween 0.05 and 0.8 μm, on the tantalum-nitride layer. When theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8001 is formed by sputtering a tantalum layer with a thickness ofbetween 0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, theseed layer at the top of the adhesion/barrier/seed layer 8001 can beformed by sputtering a gold layer with a thickness of between 0.05 and1.2 μm, and preferably of between 0.05 and 0.8 μm, on the tantalumlayer.

For example, when the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8001 is formed by sputtering a titaniumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, the seed layer at the top of theadhesion/barrier/seed layer 8001 can be formed by sputtering a copperlayer with a thickness of between 0.05 and 1.2 μm, and preferably ofbetween 0.05 and 0.8 μm, on the titanium layer. When theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8001 is formed by sputtering a titanium-tungsten-alloy layer with athickness of between 0.02 and 0.8 μm, and preferably of between 0.05 and0.5 μm, the seed layer at the top of the adhesion/barrier/seed layer8001 can be formed by sputtering a copper layer with a thickness ofbetween 0.05 and 1.2 μm, and preferably of between 0.05 and 0.8 μm, onthe titanium-tungsten-alloy layer. When the adhesion/barrier layer atthe bottom of the adhesion/barrier/seed layer 8001 is formed bysputtering a titanium-nitride layer with a thickness of between 0.02 and0.8 μm, and preferably of between 0.05 and 0.5 μm, the seed layer at thetop of the adhesion/barrier/seed layer 8001 can be formed by sputteringa copper layer with a thickness of between 0.05 and 1.2 μm, andpreferably of between 0.05 and 0.8 μm, on the titanium-nitride layer.When the adhesion/barrier layer at the bottom of theadhesion/barrier/seed layer 8001 is formed by sputtering a chromiumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, the seed layer at the top of theadhesion/barrier/seed layer 8001 can be formed by sputtering a copperlayer with a thickness of between 0.05 and 1.2 μm, and preferably ofbetween 0.05 and 0.8 μm, on the chromium layer. When theadhesion/barrier layer at the bottom of the adhesion/barrier/seed layer8001 is formed by sputtering a tantalum-nitride layer with a thicknessof between 0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm,the seed layer at the top of the adhesion/barrier/seed layer 8001 can beformed by sputtering a copper layer with a thickness of between 0.05 and1.2 μm, and preferably of between 0.05 and 0.8 μm, on thetantalum-nitride layer. When the adhesion/barrier layer at the bottom ofthe adhesion/barrier/seed layer 8001 is formed by sputtering a tantalumlayer with a thickness of between 0.02 and 0.8 μm, and preferably ofbetween 0.05 and 0.5 μm, the seed layer at the top of theadhesion/barrier/seed layer 8001 can be formed by sputtering a copperlayer with a thickness of between 0.05 and 1.2 μm, and preferably ofbetween 0.05 and 0.8 μm, on the tantalum layer.

The conduction bulk layer 8002 is formed for the low resistanceconduction, usually formed by electroplating, with a thickness between 2and 100 μm, preferred between 3 and 20 μm. The metal material of theconduction bulk layer 8002, formed by a process including anelectroplating process or an electroless plating process, comprises Au,Cu, Ag, Ni, Pd, Rh, Pt or Ru.

For example, the conduction bulk layer 8002 may be formed byelectroplating a gold layer with a thickness of between 2 and 100 μm,and preferably of between 3 and 20 μm, on the seed layer, made of gold,at the top of the adhesion/barrier/seed layer 8001. Alternatively, theconduction bulk layer 8002 may be formed by electroplating a copperlayer with a thickness of between 2 and 100 μm, and preferably ofbetween 3 and 20 μm, on the seed layer, made of copper, at the top ofthe adhesion/barrier/seed layer 8001. Alternatively, the conduction bulklayer 8002 may be formed by electroplating a copper layer with athickness of between 1.5 and 90 μm, and preferably of between 2.5 and 10μm, on the seed layer, made of copper, at the top of theadhesion/barrier/seed layer 8001, and then electroplating a gold layerwith a thickness of between 0.5 and 10 μm on the copper layer, whereinthe thickness of the copper layer and the gold layer is between 2 and100 μm, and preferably of between 3 and 20 μm. Alternatively, theconduction bulk layer 8002 may be formed by electroplating a copperlayer with a thickness of between 3 and 20 μm, and preferably of between3 and 15 μm, on the seed layer, made of copper, at the top of theadhesion/barrier/seed layer 8001, then electroplating a nickel layerwith a thickness of between 0.5 and 5 μm, and preferably of between 1and 3 μm, on the copper layer, and then electroplating a gold layer witha thickness of between 0.03 and 0.5 μm, and preferably of between 0.05and 0.1 μm, on the nickel layer. Alternatively, the conduction bulklayer 8002 may be formed by electroplating a copper layer with athickness of between 3 and 20 μm, and preferably of between 3 and 15 μm,on the seed layer, made of copper, at the top of theadhesion/barrier/seed layer 8001, then electroplating a nickel layerwith a thickness of between 0.5 and 5 μm, and preferably of between 1and 3 μm, on the copper layer, and then electroless plating a gold layerwith a thickness of between 0.03 and 0.5 μm, and preferably of between0.05 and 0.1 μm, on the nickel layer. Alternatively, the conduction bulklayer 8002 may be formed by electroplating a copper layer with athickness of between 3 and 20 μm, and preferably of between 3 and 15 μm,on the seed layer, made of copper, at the top of theadhesion/barrier/seed layer 8001, then electroplating a nickel layerwith a thickness of between 0.5 and 5 μm, and preferably of between 1and 3 μm, on the copper layer, and then electroplating a palladium layerwith a thickness of between 0.03 and 0.5 μm, and preferably of between0.05 and 0.1 μm, on the nickel layer. Alternatively, the conduction bulklayer 8002 may be formed by electroplating a copper layer with athickness of between 3 and 20 μm, and preferably of between 3 and 15 μm,on the seed layer, made of copper, at the top of theadhesion/barrier/seed layer 8001, then electroplating a nickel layerwith a thickness of between 0.5 and 5 μm, and preferably of between 1and 3 μm, on the copper layer, and then electroless plating a palladiumlayer with a thickness of between 0.03 and 0.5 μm, and preferably ofbetween 0.05 and 0.1 μm, on the nickel layer.

As an option, a cap/barrier metal layer (not shown) for protection ordiffusion barrier purpose is added. The cap/barrier layer can be formedby electroplating, electroless plating, CVD or PVD sputtered metal,preferred deposited by electroplating. The thickness of the cap/barrierlayer is of a range between 0.05 and 5 μm, preferred 0.5 and 3 μm. Thecap/barrier layer can be a Ni, Co or V layer. As another option, anassembly-contact layer (not shown) over the conduction bulk metal layer8002 and the cap/barrier layer (not shown) for assembly or packagingpurpose, especially for the top-most metal layer of the over-passivationmetals 80 (in one or more metal layers with polymer dielectric betweentwo adjacent metal layers).

Openings 990 (comprising 9919 and 9929 in the first embodiment, 9939 and9939′ in the third embodiment, 9949 and 9949′ in the fourth embodiment)in the topmost polymer layer 99 expose the surface of pads 8000(comprising 8110 and 8120 in the first embodiment, 8310 and 8320 in thethird embodiment, 8110 and 8120 in the fourth embodiment) of the topmostover-passivation metal layer. The assembly-contact metal layer iswirebodable and/or solder wettable used for wireboding, gold connection,solder ball mounting, and/or solder connection. The assembly-contactmetal layer can be Au, Ag, Pt, Pd, Rh or Ru. Joining to theassembly-contact metal layer exposed by the poymer openings 900 can be abonding wire, a solder ball (solder ball mounting), a metal ball (metalball mounting), a metal bumps on the other substrate or chip, a goldbump on the other substrate or chip, a metal post on the other substrateor chip, a copper post on the other substrate or chip.

For the conventional IC contact pads made of sputtered aluminum orelectroplated Cu (formed by CMP damascene process), the over-passivationmetal lines, traces or planes can be, as some examples, one of thefollowing stacks, from bottom to top: (1) TiW/sputtered seedAu/electroplated Au, (2) Ti/sputtered seed Au/electroplated Au, (3)Ta/sputtered seed Au/electroplated Au, (4) Cr/sputtered seedCu/electroplated Cu, (5) TiW/sputtered seed Cu/electroplated Cu, (6)Ta/sputtered seed Cu/electroplated Cu, (7) Ti/sputtered seedCu/electroplated Cu, (8) Cr. TiW, Ti or Ta/sputtered seedCu/electroplated Cu/electroplated Ni, (9) Cr, TiW, Ti or Ta/sputteredseed Cu/electroplated Cu/electroplated Ni/electroplated Au, Ag, Pt, Pd,Rh or Ru, (10) Cr, TiW, Ti or Ta/sputtered seed Cu/electroplatedCu/electroplated Ni/electroless Au, Ag, Pt, Pd, Rh or Ru. Each ofover-passivation metal layers 80 has thickness between 2 and 150 μm,preferred between 3 and 20 μm, with horizontal design rules (the width)of over-passivation metal lines or traces between 1 and 200 μm,preferred 2 and 50 μm. An over-passivation metal plane is alsopreferred, particularly for power, or ground plane, with a width greaterthan 200 μm. The minimum space between two adjacent metal lines, tracesand/or planes is between 1 and 500 μm, preferred 2 and 150 μm.

In some application of this invention, the metal lines, traces or planescan only comprise sputtered aluminum with thickness between 2 and 6 μm,preferred between 3 and 5 μm, with an optional adhesio/barrier layer(comprising Ti, TiW, TiN, Ta or TaN layer) under the aluminum layer.

Referring to FIG. 15L, as an option, a contact structure 89 is formedover the pad 8000, exposed by the opening 990, of the over-passivationmetal scheme 80. The contact structure 89 can be a metal bump, a solderbump, a solder ball, a gold bump, a copper bump, a metal pad, a solderpad, a gold pad, a metal post, a solder post, a gold post or a copperpost. Under the contact structure 89 is an adhesion/barrier layer 891.The adhesion/barrier layer 891 comprises Au, Ti, TiW, TiN, Cr, Cu, CrCu,Ta, TaN, Ni, NiV, V or Co layer, or composite layers of the abovematerials. The preferred stacks of the contact structure 89 (includingadhesion/barrier layer 891), from the bottom to the top are (1) Ti/Aupad (Au layer thickness 1-10 μm), (2) TiW/Au pad (Au layer thickness1-10 μm), (3) Ni/Au pad (Ni layer thickness 0.5 -10 μm, Au layerthickness 0.2-10 μm), (4) Ti/Au bump (Au layer thickness 7-40 μm), (5)TiW/Au bump (Au layer thickness 7-40 μm), (6) Ni/Au bump (Ni layerthickness 0.5 -10 μm, Au layer thickness 7-40cm), (7) Ti, TiW orCr/Cu/Ni/Au pad, (copper layer thickness 0.1-10 μm, Au layer thickness0.2-10 μm), (8) Ti, TiW, Cr. CrCu or NiV/Cu/Ni/Au bump, (copper layerthickness 0.1-10 μm, Au layer thickness 7-40 μm), (9) Ti, TiW, Cr, CrCuor NiV/Cu/Ni/solder pad, (copper layer thickness 0.1-10 μm, solder layerthickness 0.2 -30 μm), (10) Ti, TiW, Cr, CrCu or NiV/Cu/Ni/solder bumpor solder ball, (copper layer thickness 0.1-10 μm, solder layerthickness 10 -500 μm), (11) Ti, TiW, Cr, CrCu or NiV/Cu post, (copperlayer thickness 10 -3000 μm), (11) Ti, TiW, Cr, CrCu or NiV/Cu post/Ni,(copper layer thickness 10 -3000 μm), (12) Ti, TiW, Cr, CrCu or NiV/Cupost/Ni/Solder (copper layer thickness 10 -3000 μm, solder layerthickness 1-20 μm), (13) Ti, TiW, Cr, CrCu or NiV/Cupost/Ni/Solder(copper layer thickness 10 -3000 μm, solder layer thickness 20-100 μm).The assembly methods can be wirebonding, TAB bonding, chip-on-glass(COG), chip-on-board (COB), flip chip on BGA substrate, chip-on-film(COF), chip-on-chip stack interconnection, chip-on-Si-substrate stackinterconnection and etc.

For example, the adhesion/barrier layer 891 and the contact structure 89may be formed by sputtering a titanium-containing layer, such astitanium layer or titanium-tungsten-alloy layer, with a thickness ofbetween 0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, onthe polymer layer 99 and on the copper layer, nickel layer or gold layerof the pad 8000 exposed by the opening 990, then sputtering a seedlayer, made of gold, with a thickness of between 0.05 and 1.2 μm, andpreferably of between 0.05 and 0.8 μm, on the titanium-containing layer,then spin-on coating a photoresist layer, such as positive-typephotoresist layer, on the seed layer, then exposing the photoresistlayer using a 1× stepper or 1× contact aligner with at least two ofG-line having a wavelength ranging from 434 to 438 nm, H-line having awavelength ranging from 403 to 407 nm, and I-line having a wavelengthranging from 363 to 367 nm, illuminating the photoresist layer, that is,G-line and H-line, G-line and I-line, H-line and I-line, or G-line,H-line and I-line illuminate the photoresist layer, then developing theexposed photoresist layer, an opening in the developed photoresist layerexposing the seed layer over the pad 8000, then removing the residualpolymeric material or other contaminants from the seed layer with an O₂plasma or a plasma containing fluorine of below 200 PPM and oxygen, thenelectroplating a gold layer with a thickness of between 1 and 10 μm onthe seed layer exposed by the opening in the photoresist layer, thenremoving the developed photoresist layer using an organic solution withamide, then removing the residual polymeric material or othercontaminants from the seed layer and from the gold layer with an O₂plasma or a plasma containing fluorine of below 200 PPM and oxygen, thenremoving the seed layer not under the gold layer with a dry etchingmethod or a wet etching method, and then removing thetitanium-containing layer not under the gold layer with a dry etchingmethod or a wet etching method. As to the wet etching method, the seedlayer of gold can be etched with an iodine-containing solution, such assolution containing potassium iodide. When the titanium-containing layeris titanium layer, the titanium layer can be wet etched with a solutioncontaining hydrogen fluoride. When the titanium-containing layer istitanium-tungsten-alloy layer, the titanium-tungsten-alloy layer can bewet etched with a solution containing hydrogen peroxide. As to the dryetching method, the seed layer of gold can be removed with an ionmilling process or with an Ar sputtering etching process, and thetitanium-containing layer can be etched with a chlorine-containingplasma etching process or with an RIE process. Thereby, theadhesion/barrier metal layer 891 can be formed of thetitanium-containing layer and the seed layer, made of gold, on thetitanium-containing layer, and the contact structure 89 can be formed ofgold that is on the seed layer of the adhesion/seed layer 891.

For example, the adhesion/barrier layer 891 and the contact structure 89may be formed by sputtering a titanium-containing layer, such astitanium layer or titanium-tungsten-alloy layer, with a thickness ofbetween 0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, onthe polymer layer 99 and on the copper layer, nickel layer or gold layerof the pad 8000 exposed by the opening 990, then sputtering a seedlayer, made of copper, with a thickness of between 0.05 and 1.2 μm, andpreferably of between 0.05 and 0.8 μm, on the titanium-containing layer,then spin-on coating a photoresist layer, such as positive-typephotoresist layer, on the seed layer, then exposing the photoresistlayer using a 1× stepper or 1× contact aligner with at least two ofG-line having a wavelength ranging from 434 to 438 nm, H-line having awavelength ranging from 403 to 407 nm, and I-line having a wavelengthranging from 363 to 367 nm, illuminating the photoresist layer, that is,G-line and H-line, G-line and I-line, H-line and I-line, or G-line,H-line and I-line illuminate the photoresist layer, then developing theexposed photoresist layer, an opening in the developed photoresist layerexposing the seed layer over the pad 8000, then removing the residualpolymeric material or other contaminants from the seed layer with an O₂plasma or a plasma containing fluorine of below 200 PPM and oxygen, thenelectroplating a copper layer with a thickness of between 1 and 10 μm,and preferably of between 1 and 5 μm, on the seed layer exposed by theopening in the photoresist layer, then electroplating a nickel layerwith a thickness of between 0.5 and 5 μm, and preferably of between 0.5and 1 μm, on the copper layer in the opening, then electroplating atin-containing layer, such as a tin-lead alloy, a tin-silver alloy or atin-silver-copper alloy, with a thickness of between 50 and 150 μm, andpreferably of between 80 and 130 μm, on the nickel layer in the opening,then removing the developed photoresist layer using an organic solutionwith amide, then removing the residual polymeric material or othercontaminants from the seed layer and from the tin-containing layer withan O₂ plasma or a plasma containing fluorine of below 200 PPM andoxygen, then removing the seed layer not under the copper layer with adry etching method or a wet etching method, then removing thetitanium-containing layer not under the copper layer with a dry etchingmethod or a wet etching method, and then reflowing the tin-containinglayer. As to the wet etching method, the seed layer of copper can beetched with a solution containing NH₄OH. When the titanium-containinglayer is titanium layer, the titanium layer can be wet etched with asolution containing hydrogen fluoride. When the titanium-containinglayer is titanium-tungsten-alloy layer, the titanium-tungsten-alloylayer can be wet etched with a solution containing hydrogen peroxide. Asto the dry etching method, the seed layer of copper can be removed withan Ar sputtering etching process, and the titanium-containing layer canbe etched with a chlorine-containing plasma etching process or with anRIE process. Thereby, the adhesion/barrier layer 891 can be formed ofthe titanium-containing layer and the seed layer, made of copper, on thetitanium-containing layer, and the contact structure 89 can be formed ofthe copper layer on the seed layer, the nickel layer on the copperlayer, and the tin-containing layer on the nickel layer. For example,the adhesion/barrier layer 891 and the contact structure 89 may beformed by sputtering a chromium layer with a thickness of between 0.02and 0.8 μm, and preferably of between 0.05 and 0.5 μm, on the polymerlayer 99 and on the copper layer, nickel layer or gold layer of the pad8000 exposed by the opening 990, then sputtering a seed layer, made ofcopper, with a thickness of between 0.05 and 1.2 μm, and preferably ofbetween 0.05 and 0.8 μm, on the chromium layer, then spin-on coating aphotoresist layer, such as positive-type photoresist layer, on the seedlayer, then exposing the photoresist layer using a 1× stepper or 1×contact aligner with at least two of G-line having a wavelength rangingfrom 434 to 438 nm, H-line having a wavelength ranging from 403 to 407nm, and I-line having a wavelength ranging from 363 to 367 nm,illuminating the photoresist layer, that is, G-line and H-line, G-lineand I-line, H-line and I-line, or G-line, H-line and I-line illuminatethe photoresist layer, then developing the exposed photoresist layer, anopening in the developed photoresist layer exposing the seed layer overthe pad 8000, then removing the residual polymeric material or othercontaminants from the seed layer with an O₂ plasma or a plasmacontaining fluorine of below 200 PPM and oxygen, then electroplating acopper layer with a thickness of between 1 and 10 μm, and preferably ofbetween 1 and 5 μm, on the seed layer exposed by the opening in thephotoresist layer, then electroplating a nickel layer with a thicknessof between 0.5 and 5 μm, and preferably of between 0.5 and 1 μm, on thecopper layer in the opening, then electroplating a tin-containing layer,such as a tin-lead alloy, a tin-silver alloy or a tin-silver-copperalloy, with a thickness of between 50 and 150 μm, and preferably ofbetween 80 and 130 μm, on the nickel layer in the opening, then removingthe developed photoresist layer using an organic solution with amide,then removing the residual polymeric material or other contaminants fromthe seed layer and from the tin-containing layer with an O₂ plasma or aplasma containing fluorine of below 200 PPM and oxygen, then removingthe seed layer not under the copper layer with a dry etching method or awet etching method, then removing the chromium layer not under thecopper layer with a dry etching method or a wet etching method, and thenreflowing the tin-containing layer. As to the wet etching method, theseed layer of copper can be etched with a solution containing NH₄OH, andthe chromium layer can be etched with a solution containing potassiumferricyanide. As to the dry etching method, the seed layer of copper canbe removed with an Ar sputtering etching process. Thereby, theadhesion/barrier layer 891 can be formed of the chromium layer and theseed layer, made of copper, on the chromium layer, and the contactstructure 89 can be formed of the copper layer on the seed layer, thenickel layer on the copper layer, and the tin-containing layer on thenickel layer.

For example, the adhesion/barrier layer 891 and the contact structure 89may be formed by sputtering a tantalum-containing layer, such astantalum layer or tantalum-nitride layer, with a thickness of between0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, on thepolymer layer 99 and on the copper layer, nickel layer or gold layer ofthe pad 8000 exposed by the opening 990, then sputtering a seed layer,made of copper, with a thickness of between 0.05 and 1.2 μm, andpreferably of between 0.05 and 0.8 μm, on the tantalum-containing layer,then spin-on coating a photoresist layer, such as positive-typephotoresist layer, on the seed layer, then exposing the photoresistlayer using a 1× stepper or 1× contact aligner with at least two ofG-line having a wavelength ranging from 434 to 438 nm, H-line having awavelength ranging from 403 to 407 nm, and I-line having a wavelengthranging from 363 to 367 nm, illuminating the photoresist layer, that is,G-line and H-line, G-line and I-line, H-line and I-line, or G-line,H-line and I-line illuminate the photoresist layer, then developing theexposed photoresist layer, an opening in the developed photoresist layerexposing the seed layer over the pad 8000, then removing the residualpolymeric material or other contaminants from the seed layer with an O₂plasma or a plasma containing fluorine of below 200 PPM and oxygen, thenelectroplating a copper layer with a thickness of between 1 and 10 μm,and preferably of between 1 and 5 μm, on the seed layer exposed by theopening in the photoresist layer, then electroplating a nickel layerwith a thickness of between 0.5 and 5 μm, and preferably of between 0.5and 1 μm, on the copper layer in the opening, then electroplating atin-containing layer, such as a tin-lead alloy, a tin-silver alloy or atin-silver-copper alloy, with a thickness of between 50 and 150 μm, andpreferably of between 80 and 130 μm, on the nickel layer in the opening,then removing the developed photoresist layer using an organic solutionwith amide, then removing the residual polymeric material or othercontaminants from the seed layer and from the tin-containing layer withan O₂ plasma or a plasma containing fluorine of below 200 PPM andoxygen, then removing the seed layer not under the copper layer with adry etching method or a wet etching method, then removing thetantalum-containing layer not under the copper layer with a dry etchingmethod or a wet etching method, and then reflowing the tin-containinglayer. As to the wet etching method, the seed layer of copper can beetched with a solution containing NH₄OH. As to the dry etching method,the seed layer of copper can be removed with an Ar sputtering etchingprocess. Thereby, the adhesion/seed metal layer 891 can be formed of thetantalum-containing layer and the seed layer, made of copper, on thetantalum-containing layer, and the contact structure 89 can be formed ofthe copper layer on the seed layer, the nickel layer on the copperlayer, and the tin-containing layer on the nickel layer.

For example, the adhesion/barrier layer 891 and the contact structure 89may be formed by sputtering a titanium-containing layer, such astitanium layer or titanium-tungsten-alloy layer, with a thickness ofbetween 0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, onthe polymer layer 99 and on the copper layer, nickel layer or gold layerof the pad 8000 exposed by the opening 990, then sputtering a seedlayer, made of copper, with a thickness of between 0.05 and 1.2 μm, andpreferably of between 0.05 and 0.8 μm, on the titanium-containing layer,then spin-on coating a photoresist layer, such as positive-typephotoresist layer, on the seed layer, then exposing the photoresistlayer using a 1× stepper or 1× contact aligner with at least two ofG-line having a wavelength ranging from 434 to 438 nm, H-line having awavelength ranging from 403 to 407 nm, and I-line having a wavelengthranging from 363 to 367 nm, illuminating the photoresist layer, that is,G-line and H-line, G-line and I-line, H-line and I-line, or G-line,H-line and I-line illuminate the photoresist layer, then developing theexposed photoresist layer, an opening in the developed photoresist layerexposing the seed layer over the pad 8000, then removing the residualpolymeric material or other contaminants from the seed layer with an O₂plasma or a plasma containing fluorine of below 200 PPM and oxygen, thenelectroplating a nickel layer with a thickness of between 0.5 and 5 μm,and preferably of between 0.5 and 1 μm, on the seed layer exposed by theopening in the photoresist layer, then electroplating a tin-containinglayer, such as a tin-lead alloy, a tin-silver alloy or atin-silver-copper alloy, with a thickness of between 50 and 150 μm, andpreferably of between 80 and 130 μm, on the nickel layer in the opening,then removing the developed photoresist layer using an organic solutionwith amide, then removing the residual polymeric material or othercontaminants from the seed layer and from the tin-containing layer withan O₂ plasma or a plasma containing fluorine of below 200 PPM andoxygen, then removing the seed layer not under the copper layer with adry etching method or a wet etching method, then removing thetitanium-containing layer not under the copper layer with a dry etchingmethod or a wet etching method, and then reflowing the tin-containinglayer. As to the wet etching method, the seed layer of copper can beetched with a solution containing NH₄OH. When the titanium-containinglayer is titanium layer, the titanium layer can be wet etched with asolution containing hydrogen fluoride. When the titanium-containinglayer is titanium-tungsten-alloy layer, the titanium-tungsten-alloylayer can be etched with a solution containing hydrogen peroxide. As tothe dry etching method, the seed layer of copper can be removed with anAr sputtering etching process, and the titanium-containing layer can beetched with a chlorine-containing plasma etching process or with an RIEprocess. Thereby, the adhesion/barrier layer 891 can be formed of thetitanium-containing layer and the seed layer, made of copper, on thetitanium-containing layer, and the contact structure 89 can be formed ofthe nickel layer on the seed layer and the tin-containing layer on thenickel layer.

For example, the adhesion/barrier layer 891 and the contact structure 89may be formed by sputtering a chromium layer with a thickness of between0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, on thepolymer layer 99 and on the copper layer, nickel layer or gold layer ofthe pad 8000 exposed by the opening 990, then sputtering a seed layer,made of copper, with a thickness of between 0.05 and 1.2 μm, andpreferably of between 0.05 and 0.8 μm, on the chromium layer, thenspin-on coating a photoresist layer, such as positive-type photoresistlayer, on the seed layer, then exposing the photoresist layer using a 1×stepper or 1× contact aligner with at least two of G-line having awavelength ranging from 434 to 438 nm , H-line having a wavelengthranging from 403 to 407 nm, and I-line having a wavelength ranging from363 to 367 nm, illuminating the photoresist layer, that is, G-line andH-line, G-line and I-line, H-line and I-line, or G-line, H-line andI-line illuminate the photoresist layer, then developing the exposedphotoresist layer, an opening in the developed photoresist layerexposing the seed layer over the pad 8000, then removing the residualpolymeric material or other contaminants from the seed layer with an O₂plasma or a plasma containing fluorine of below 200 PPM and oxygen, thenelectroplating a nickel layer with a thickness of between 0.5 and 5 μm,and preferably of between 0.5 and 1 μm, on the seed layer exposed by theopening in the photoresist layer, then electroplating a tin-containinglayer, such as a tin-lead alloy, a tin-silver alloy or atin-silver-copper alloy, with a thickness of between 50 and 150 μm, andpreferably of between 80 and 130 μm, on the nickel layer in the opening,then removing the developed photoresist layer using an organic solutionwith amide, then removing the residual polymeric material or othercontaminants from the seed layer and from the tin-containing layer withan O₂ plasma or a plasma containing fluorine of below 200 PPM andoxygen, then removing the seed layer not under the copper layer with adry etching method or a wet etching method, then removing the chromiumlayer not under the copper layer with a dry etching method or a wetetching method, and then reflowing the tin-containing layer. As to thewet etching method, the seed layer of copper can be etched with asolution containing NH₄OH, and the chromium layer can be etched with asolution containing potassium ferricyanide. As to the dry etchingmethod, the seed layer of copper can be removed with an Ar sputteringetching process. Thereby, the adhesion/barrier layer 891 can be formedof the chromium layer and the seed layer, made of copper, on thechromium layer, and the contact structure 89 can be formed of the nickellayer on the seed layer and the tin-containing layer on the nickellayer.

For example, the adhesion/barrier layer 891 and the contact structure 89may be formed by sputtering a tantalum-containing layer, such astantalum layer or tantalum-nitride layer, with a thickness of between0.02 and 0.8 μm, and preferably of between 0.05 and 0.5 μm, on thepolymer layer 99 and on the copper layer, nickel layer or gold layer ofthe pad 8000 exposed by the opening 990, then sputtering a seed layer,made of copper, with a thickness of between 0.05 and 1.2 μm, andpreferably of between 0.05 and 0.8 μm, on the tantalum-containing layer,then spin-on coating a photoresist layer, such as positive-typephotoresist layer, on the seed layer, then exposing the photoresistlayer using a 1× stepper or 1× contact aligner with at least two ofG-line having a wavelength ranging from 434 to 438 nm , H-line having awavelength ranging from 403 to 407 nm, and I-line having a wavelengthranging from 363 to 367 nm, illuminating the photoresist layer, that is,G-line and H-line, G-line and I-line, H-line and I-line, or G-line,H-line and I-line illuminate the photoresist layer, then developing theexposed photoresist layer, an opening in the developed photoresist layerexposing the seed layer over the pad 8000, then removing the residualpolymeric material or other contaminants from the seed layer with an O₂plasma or a plasma containing fluorine of below 200 PPM and oxygen, thenelectroplating a nickel layer with a thickness of between 0.5 and 5 μm,and preferably of between 0.5 and 1 μm, on the seed layer exposed by theopening in the photoresist layer, then electroplating a tin-containinglayer, such as a tin-lead alloy, a tin-silver alloy or atin-silver-copper alloy, with a thickness of between 50 and 150 μm, andpreferably of between 80 and 130 μm, on the nickel layer in the opening,then removing the developed photoresist layer using an organic solutionwith amide, then removing the residual polymeric material or othercontaminants from the seed layer and from the tin-containing layer withan O₂ plasma or a plasma containing fluorine of below 200 PPM andoxygen, then removing the seed layer not under the copper layer with adry etching method or a wet etching method, then removing thetantalum-containing layer not under the copper layer with a dry etchingmethod or a wet etching method, and then reflowing the tin-containinglayer. As to the wet etching method, the seed layer of copper can beetched with a solution containing NH₄OH. As to the dry etching method,the seed layer of copper can be removed with an Ar sputtering etchingprocess. Thereby, the adhesion/barrier layer 891 can be formed of thetantalum-containing layer and the seed layer, made of copper, on thetantalum-containing layer, and the contact structure 89 can be formed ofthe nickel layer on the seed layer and the tin-containing layer on thenickel layer.

There is another important feature of the over-passivation scheme 8:using polymer material as the dielectric or insulating layer 90, over,under or between the over-passivation metal layers 80. Referring to FIG.15K, use of polymer layers 90 (comprising 95, 98 and 99 in allembodiments of this invention) provides the possibility of fabricatingthicker than 2 μm dielectric layer. The thickness of the polymer layer90 can be between 2 and 100 μm, and preferably of between 3 and 30 μm.The polymer layers 90 used in the over-passivationscheme 8 can bepolyimide (PI), benzocyclobutene (BCB), elastomer (such as silicone),parylene, epoxy-based material (such as photoepoxy SU-8 supplied bySotec Microsystems, Renens, Switzerland). A solder mask material used inthe printing circuit board industry can be used as the cap layer 99 (thetopmost polymer layer over all the over-passivation metal layers 80). Aphotosensitive polyimide can be used as the polymer layers 90(comprising 95, 98 and 99 in all embodiments of this invention).Furthermore, the polymer layers 90 (comprising 95, 98 and 99 in allembodiments of this invention) can be a non-ionic polymide, such as anether-based polyimide, PIMEL™, supplied by Asahi Chemical, Japan. Copperdoes not diffuse or penetrate through the non-ionic polyimide,therefore, it is allowed to have a direct contact between copper andpolyimide. With the non-ionic polyimide, spacing between copper lines ortraces or planes in the over-passivation metal scheme 80 can be as closeas 1 μm, i.e. the spacing between two metal traces or planes can begreater 1 μm. Furthermore, no protection cap, such as a Ni cap layer,over the copper layer is required for copper lines, or traces, orplanes.

Referring to FIG. 15K now, openings 900 in the polymer layers 90 areformed for interconnection between different over-passivation metallayers 80, or for connection to the underlying fine-line metal layers60, or for connection to an external circuits. The polymer openings 900(including 950, 980 and 990) comprises (1) 9919, 9929, 9829, 9519,9519′, 9511, 9512 and 9514 in the first embodiment; (2) 9831, 9834,9531, 9532 and 9534 in the second embodiment; (3) 9939, 9939′, 9839,9831, 9834, 9539, 9539′, 9531, 9532 and 9534 in the third embodiment;and (4) 9949, 9949′, 9849′, 9511, 9512, 9514 and 9549 in the fourthembodiment. The material of the polymer layers 90 can be aphoto-sensitive or non-photo-sensitive. For the photo-sensitive polymerlayers 90, the polymer openings 900 are defined and patterned by lightexposure and developing. While for the non-photo-sensitive polymer layer90, the openings 900 are defined by first coating a photoresist layerover the polymer layer, exposing and developing the photoresist tocreate openings in the photoresist, wet or dry etching the polymer layerexposed by the potoresist openings, creating openings 900 in the polymerlayer 90, and then stripping the photoresist. The width of the polymeropenings 900 is between 2 and 1,000 μm, preferred between 5 and 200 μm.In some designs, the polymer layer 90 may be removed in a large withdimension larger than 1,000 μm. The openings 900 are designed incircles, corner-rounded squares, rectangles, or polygons.

The polymer layer 95 is between the passivation layer 5 and thebottom-most over-passivation metal layer 801. Through openings 950 inthe polymer layer 95, the signal, power (Vdd or Vcc) and/or ground (Vss)passes between the fine-line metal scheme 6 and the over-passivationmetal scheme 80. The process for forming the openings 950 in the polymerlayer 95 can be applied to the process for (1) forming the openings9519, 9519′, 9511, 9512 and 9514 in FIG. 3D in the polymer layer 95; (2)froming the openings 9531, 9532 and 9534 in FIG. 7D in the polymer layer95; (3) forming the openings 9539, 9539′, 9531, 9532 and 9534 in FIGS.10D, 10E, 10G, 10H and 10I in the polymer layer 95; or (4) forming theopening 9549, 9511, 9512 and 9514 in FIG. 14D in the polymer layer 95.The width of the polymer openings 9531, 9532, 9534, 9511, 9512 and 9514,aligned with the passivation openings 531, 532, 534, 511, 512 and 514,respectively, for the internal circuits 20 (including 21, 22, 23 and 24)is between 1 and 3000 μm, preferred between 3 and 100 μm. The width ofthe openings 9519 and 9519′, aligned with the openings 519 and 519′,respectively, for the voltage regulator or voltage converter 41, thewidth of the openings 9539 and 9539′, aligned with the openings 539 and539′, respectively, for the off-chip circuits 40 (including 42 and 43),or the width of the opening 9549, aligned with the opening 549,respectively, for the ESD circuit 44 may be greater than those of theopenings 9531, 9532, 9534, 9511, 9512 and 9514, in a range between 5 and1,000 μm, preferred 10 and 200 μm. Note that two types of stacked viasof a polymer opening 950 over a passivation opening 50. In a first typeof stacked vias, the polymer openings, for example the opening 9531shown in FIG. 10E, has a width larger than that of the underlyingpassivation opening 531 shown in FIG. 10E. The opening 9531 exposes atop surface of the passivation layer 5 adjacent to the contact pad 6390exposed by the opening 531, in addition to exposing the contact pad6390. In this case, a smaller passivation opening 531 can be formed;hence a smaller contact pad of the top-most fine-line metal layer 60 canbe formed. This type of stacked vias allows higher routing density ofthe top-most fine-line metal layer 60. In a second type of stacked vias,the polymer openings, for example the opening 9539 shown in FIG. 10E, issmaller than the underlying passivation opening 539 shown in FIG. 10E.The polymer layer 95 covers a peripheral region of the contact pad 6390exposed by the opening 539 and the passivation layer 5, an opening 9531in the polymer layer 95 exposing a center region of the contact pad 6390exposed by the opening 539. In this type, the polymer layer 95 coversthe sidewall of the passivation openings. The sidewall of the polymeropenings provides a gentle, better slope than the slope of thepassivation opening sidewall, and resulting in a better step coveragefor the subsequent metal sputtering for the adhesion/barrier/seed layer8011. A better adhesion/barrier metal step coverage is important for thereliability of the chip, since it prevent the inter-metallic compound(IMC) from happening.

The openings 980 in the polymer layer 98 are between twoover-passivation metal layers 801 and 802. The process for forming theopenings 980 in the polymer layer 98 can be applied to the process for(1) forming the opening 9829 in FIG. 3C in the polymer layer 98; (2)forming the openings 9831 and 9834 in FIG. 7C in th polymer layer 98;(3) forming the openings 9831, 9834 and 9839 in FIGS. 10C and 10E in thepolymer layer 98; or (4) forming the opening 9849′ in FIG. 14C in thepolymer layer 98. The width of the polymer openings 9831 and 9834 forthe internal circuits 20 (comprising 21, 22, 23 and 24) is between 1 and3000 μm, preferred between 3 and 100 μm. The width of the polymeropening 9829 for the voltage regulator or voltage converter 41, thewidth of the polymer opening 9839 for the off-chip circuits 40(including 42 and 43), or the width of the polymer opening 9849′ for theESD circuit 44 may be greater than those of the openings 9831 and 9834,in a range between 5 and 1,000 μm, preferred 10 and 200 μm.

The opening 990 in the cap polymer layer 99 exposes the pad 8000 of thetop-most metal layer 802 for connecting to the external circuits or forthe probe contacting in chip testing. The process for forming theopenings 990 in the polymer layer 99 can be applied to the process for(1) forming the opening 9919 in FIGS. 3B and 3D in the polymer layer 99;(2) forming the opening 9929 in FIG. 3C in the polymer layer 99; (3)forming the opening 9939 in FIGS. 10B, 10D, 10F, 10G, 10H and 10I in thepolymer layer 99; (4) forming the opening 9939′ in FIGS. 10C and 10E inthe polymer layer 99; (5) forming the opening 9949 in FIGS. 14B and 14Din the polymer layer 99; or (6) forming the opening 9949′ in FIG. 14C inthe polymer layer 99. There are no openings in the cap polymer layer 99for the internal circuits 20 (comprising 21, 22, 23 and 24) beingconnected to an external circuit. The width of the polymer openings 9919and 9929 for the voltage regulator or voltage converter 41, the width ofthe polymer openings 9939 and 9939′ for the off-chip circuits 40(comprising 42 and 43), or the width of the polymer openings 9949 and9949′ for the ESD circuit 44, can be in a range between 5 and 1,000 μm,preferred 10 and 200 μm.

The signal, power or ground stimuli in the over-passivation metal layers80 of the over-passivation scheme 8 is delivered to the internalcircuits 20, the voltage regulators or voltage converters 41, theoff-chip circuits 40 or the ESD circuits 44 through the fine-line scheme6. The fine-line metals 631, 632, 634, 639 and 639′ shown in FIG. 15Acan be composed of stacked via plugs 60′, wherein preferably, the upperone may be directly over the lower one. Alternative, the fine-line metal632 may comprise a local fine-line metal layer 632 c shown in FIG. 15A,and as well as in all embodiments of this invention.

The photolithography used to fabricate the over-passivation scheme 8 issignificantly different from that of convention IC process. Similarly,the over-passivation photolithography process comprises coating,exposing and developing the photoresist. Two types of photoresist areused to form the over-passivation scheme 8: (1) liquid photoresist,formed by one or multiple spin-on coating, or printing. The liquidphotoresist has a thickness between 3 and 60 μm, preferred between 5 and40μm; (2) dry-film photoresist, formed by a laminating method. Thedry-film photoresist has a thickness between 30 and 3000 μm, preferredbetween 50 and 150 μm. The photoresit can be positive-type ornegative-type, preferred positive-type thick photoresist for betterresolution. If the polymer is photo-sensitive, the same photolithographyprocess for the photoresist can be applied to pattern the polymer. Analigner or 1 X stepper exposes the phoresist. The 1× means that thedimension on a photo mask (usual made of quartz or glass) is reduced onthe wafer when light beam is projected from the photo mask onto thewafer, and the dimension of a feature on the photo mask is the same ofthe dimension on the wafer. The wavelength of the light beam used in thealigner or 1× stepper is 436 nm (g-line), 397 nm (h-line), 365 nm(i-line), g/h-line (combination of g-line and h-line), or g/h/i-line(combination of g-line, h-line and i-line). The g/h-line or g/h/i-line1× stepper (or 1× aligner) provides strong light intensity for thickphotoresist or thick photo-sensitive polymer exposure.

Sine the passivation layer 5 protects underlying MOS transistors andfine-line scheme 6 from the penetration of moisture, sodium or othermobile ions, gold, copper or other transition metals, theover-passivation scheme 8 on conventional IC chip of an IC wafer can beprocessed in a clean room with Class 10 or less stringent environment,for example Class 100. A Class 100 clean room allows maximum number ofparticles per cubic foot: 1 larger than 5 μm, 10 larger than 1 μm, 100larger than 0.5 μm, 3000 larger than 0.3 μm, 750 larger than 0.2 μm,3500 larger than 0.1μm.

The device layer 2 comprises the internal circuits 20 (comprising 21,22, 23 and 24) in all embodiments, the regulator or voltage converter 41in the first embodiment, the off-chip circuits 40 (comprising 42 and 43)in the third embodiment, and the ESD circuit 44 in the fourthembodiment.

An internal circuit or an internal circuit unit 20, comprising 21, 22,23 and 24, in all embodiments of this invention, is defined as a circuitwhose signal nodes are not connected to the external (outside the chip)circuits. If a signal of an internal circuit or internal circuit unit 20needs to connect to an external circuit, it must go through an off-chipcircuit first, for example, ESD circuits, off-chip drivers or off-chipreceivers and/or other off-chip I/O circuits, before connecting to theexternal circuit. In other definition, the internal circuits or theinternal circuit units 20 do not comprise off-chip circuits. Theinternal circuits or internal circuit units 20, comprising 21, 22, 23and 24, in this invention may, in addition to a NOR gate and a NANDgate, be an inverter, an AND gate, an OR gate, an SRAM cell, a DRAMcell, a non-volatile memory cell, a flash memory cell, a EPROM cell, aROM cell, a magnetic RAM (MRAM) cell, a sense amplifier, an operationalamplifier, an adder, a multiplexer, a diplexer, a multiplier, an A/Dconverter, a D/A converter, or other CMOS, BiCMOS, and/or bipolarcircuit, analog circuit, a CMOS sensor cell, or a photo-sensitive diode.

Moreover, an internal circuit or an internal circuit unit 20 can bedefined by its peak input or output current, or it can be defined as itsMOS transistor size, as discussed in the third embodiment. The off-chipcircuits 40, comprising 42, 43, can also be defined by its peak input oroutput current, or defined as its MOS transistor size, also as discussedin the third embodiment. The definition of the internal circuit 20 andthe off-chip circuit 40 apply to all other embodiments in thisinvention.

In a case, a gate of a MOS device may be connected to another gate ofanother MOS device through the above mentioned thick and wide metaltrace, bus or plane 81, 81P, 82, 83, 83′ or 85 over the passivationlayer 5. In another case, a gate of a MOS device may be connected to asource of another MOS device through the above mentioned thick and widemetal trace, bus or plane 81, 81P, 82, 83, 83′ or 85 over thepassivation layer 5. In another case, a gate of a MOS device may beconnected to a drain of another MOS device through the above mentionedthick and wide metal trace, bus or plane 81, 81P, 82, 83, 83′ or 85 overthe passivation layer 5. In another case, a source of a MOS device maybe connected to another source of another MOS device through the abovementioned thick and wide metal trace, bus or plane 81, 81P, 82, 83, 83′or 85 over the passivation layer 5. In another case, a source of a MOSdevice may be connected to a drain of another MOS device through theabove mentioned thick and wide metal trace, bus or plane 81, 81P, 82,83, 83′ or 85 over the passivation layer 5. In another case, a drain ofa MOS device may be connected to another drain of another MOS devicethrough the above mentioned thick and wide metal trace, bus or plane 81,81P, 82, 83, 83′ or 85 over the passivation layer 5.

In following paragraphs, the dimension of features and electricalcharacteristics are described and compared between metal lines or metaltraces 80, 60 in the over-passivation scheme 8 and in the fine-linescheme 6 for all embodiments in this invention:

-   -   (1). Thickness of metal lines, metal traces: Each of the        over-passivation metal layers 80 has thickness between 2 and 150        μm, preferred between 3 and 20 μm, while each of the fin-line        metal layers 60 has thickness between 0.05 and 2 μm, preferred        between 0.2 and 1 μm. For an IC chip designed with embodiments        in this invention, the thickness of an over-passivation metal        line or metal trace is thicker than the thickness of any        fine-line metal lines or metal traces, with the thickness ratio        in a range between 2 and 250, preferred between 4 and 20.    -   (2). Thickness of dielectric layers: Each of the        over-passivation dielectric (usually an organic material, such        as polymer) layers 90 has thickness between 2 and 150 μm,        preferred between 3 and 30 μm, while each of the fine-line        dielectric (usually inorganic material, such as oxide or        nitride) layers 30 has thickness between 0.05 and 2 μm,        preferred between 0.2 and 1 μm. For an IC chip designed with        embodiments in this invention, the thickness of an        over-passivation dielectric layer 90 (separated by two        neighboring metal layers) is thicker than the thickness of any        fine-line dielectric layer 30 (separated by two neighboring        metal layers), with the thickness ratio in a range between 2 and        250, preferred between 4 and 20.    -   (3). Sheet resistance and resistance of metal lines or metal        traces: Sheet resistance of a metal line or metal trace is        computed by dividing metal resistivity by metal thickness. The        sheet resistance of a copper (5 μm thick) over-passivation metal        line or trace is about 4 mili-ohms per square, while for a gold        (4 μm thick) over-passivation metal line or trace is about 5.5        mili-ohms per square. The sheet resistance of an        over-passivation metal line, or trace, or plane is in a range        between 0.1 and 10 mili-ohms per square, preferred between 1 and        7 mili-ohms per square. The sheet resistance of a sputtered        aluminum (0.8 μm thick) fine-line metal line or trace is about        35 mili-ohms per square, while for a damascene copper (0.9 μm        thick) fine-line metal line or trace is about 20 mili-ohms per        square. The sheet resistance of a fine-line metal line, or        trace, or plane is in a range between 10 and 400 mili-ohms per        square, preferred between 15 and 100 mili-ohms per square. The        resistance per unit length of a metal line or trace is        calculated by dividing the sheet resistance by its width. The        horizontal design rules (the width) of over-passivation metal        lines or traces between 1 and 200 μm, preferred 2 and 50 μm,        while the horizontal design rules (the width) of lines or traces        between 20 nano-meter and 15 μm, preferred 20 nano-meter and 2        μm. The resistance per mm of an over-passivation metal line or        trace is between 2 mili-ohms per mm length and 5 ohms per mm        length, preferred between 50 mili-ohms per mm length and 2.5        ohms per mm length. The resistance per mm of a fine-line metal        line or trace is between 1 ohm per mm length and 3,000 ohms per        mm length, preferred between 500 mili-ohms per mm length and 500        ohms per mm length. For an IC chip designed with embodiments in        this invention, the resistance per unit length of an        over-passivation metal line or metal trace is smaller than that        of any fine-line metal lines or metal traces, with the ratio of        resistance per unit length (fine-line to over-passivation) in a        range between 3 and 250, preferred between 10 and 30.    -   (4). Capacitance per unit length of metal lines or metal traces:        Capacitance per unit length is related to dielectric types,        thickness, and metal line width, spacing, and thickness, and the        surrounding metals in horizontal and vertical directions. The        dielectric constant of polyimide is about 3.3 ; the dielectric        constant of BCB is about 2.5. FIG. 20 shows an example of a        typical over-passivation metal line or trace 802 x with two        neighboring metal lines or traces 802 y and 802 z on both sides        on the same metal layer 802, and a metal line or trace 801 w on        a metal layer 801 under the metal layer 802, separating by a        polymer layer 98. Similarly, FIG. 20 shows an example of a        typical fine-line metal line or trace 602 x with two neighboring        metal lines or traces 602 y and 602 z on both sides on the same        metal layer 602, and a metal line or trace 601 w on a metal        layer 601 under the metal layer 602, separating by a dielectric        layer 30. The typical capacitance per unit length of the typical        metal lines or traces 802 x, 602 x comprise three components: 1)        plate capacitance, Cxw (pF/mm) which is a function of the metal        width to dielectric thickness aspect ratio, 2) coupling        capacitance, Ccx (=Cxy+Cxz), which is a function of the metal        thickness to line spacing aspect ratio, and 3) fringing        capacitance, Cfx (=Cfl+Cfr), which is a function of metal        thickness, spacing, and dielectric thickness. The capacitance        per mm of an over-passivation metal line or trace is between 0.1        pF (pico Farads) per mm length and 2 pF per mm length, preferred        between 0.3 pF per mm length and 1.5 pF per mm length. The        capacitance per mm of a fine-line metal line or trace is between        0.2 pF per mm length and 4 pF per mm length, preferred between        0.4 pF per mm length and 2 pF per mm length. For an IC chip        designed with embodiments in this invention, the capaciatnce per        unit length of an over-passivation metal line or metal trace is        smaller than that of any fine-line metal lines or metal traces,        with the ratio of capcitance per unit length (fine-line to        over-passivation) in a range between 1.5 and 20, preferred        between 2 and 10.    -   (5). RC constant of metal lines or metal traces: The signal        propagation time on a metal line or metal trace is computed by        the RC delay. Based on the description of previous two        paragraphs (3) and (4), the RC delay in an over-passivation        metal line or trace is in a range between 0.003 and 10 ps (pico        second) per mm length, preferred between 0.25 and 2 ps (pico        second) per mm length; while the RC delay in a fine-line metal        line or trace is in a range between 10 and 2,000 ps (pico        second) per mm length, preferred between 40 and 500 ps (pico        second) per mm length. For an IC chip designed with embodiments        in this invention, the RC paopagation time per unit length of an        over-passivation metal line or metal trace is smaller than that        of any fine-line metal lines or metal traces, with the ratio of        RC propagation delay time per unit length (fine-line to        over-passivation) in a range between 5 and 500, preferred        between 10 and 30.

FIGS. 15C-15K show the process steps to form the over-passivation scheme8 on the conventional finished IC chip 10 shown in FIG. 15A or FIG. 15B.Each of the over-passivation metal layers 80 is formed by an embossingprocess (as contrast to the damascene copper process under thepassivation layer 5 ).

Referring to FIG. 15C, a polymer layer 95 is deposited on thepassivation layer 5 and on the metal pads 600 exposed by the passivationopenings 50 of the conventional finished IC chip 10. If the polymerlayer 95 is in liquid form, it can be deposited by spin-on coating orprinting. If the polymer layer 95 is a dry film, the dry film is formedby a laminating method. For a photo-sensitive polymer, the polymer layer95 is exposed by light of an aligner or a 1× stepper through a photomask. The polymer layer 95 is developed to form openings 950 in thepolymer layer 95. If the polymer is non-photo-sensitive, a conventionalphotolithography process using a photoresist is required to pattern theopenings 950. A hard mask (such as a silicon oxide layer, not shown),with a slow differentiating etch rate during the polymer opening etch,may optionally be deposited on the polymer layer 95 before coating thephoresist. As an alternative, the patterned polymer layer 95 (that is apolymer layer with openings 950) can also be formed by screeningprinting methods using a metal screen with patterned holes. No exposureand developing are required in the screen-printing method. If thepolymer layer 95 is a dry film, as another alternative, holes can beformed in a sheet of dry film before laminated on the wafer. No exposureand developing are required in this alternative.

For example, the polymer layer 95 can be formed by spin-on coating anegative-type photosensitive polyimide layer, containing ester-typerprecursor, having a thickness of between 6 and 50 μm on the passivationlayer 5 and on the metal pads 600 exposed by the passivation openings50, then baking the spin-on coated polyimide layer, then exposing thebaked polyimide layer using a 1× stepper or 1× contact aligner with atleast two of G-line having a wavelength ranging from 434 to 438 nm ,H-line having a wavelength ranging from 403 to 407 nm, and I-line havinga wavelength ranging from 363 to 367 nm, illuminating the bakedpolyimide layer, that is, G-line and H-line, G-line and I-line, H-lineand I-line, or G-line, H-line and I-line illuminate the baked polyimidelayer, then developing the exposed polyimide layer to form polyimideopenings in the exposed polyimide layer exposing the pads 600, thencuring or heating the developed polyimide layer at a peak temperature ofbetween 290 and 400° C. for a time of between 20 and 150 minutes in anitrogen ambient or in an oxygen-free ambient, the cured polyimide layerhaving a thickness of between 3 and 25 μm, and then removing theresidual polymeric material or other contaminants from the upper surfaceof the pads 600 exposed by the polyimide opening with an O₂ plasma or aplasma containing fluorine of below 200 PPM and oxygen, such that thepolymer layer 95 can be patterned with openings 950 in the polymer layer95 exposing the pads 600. Alternatively, the developed polyimide layercan be cured or heated at a temperature between 150 and 290° C., andpreferably of between 260 and 280° C., for a time of between 20 and 150minutes in a nitrogen ambient or in an oxygen-free ambient.

The polymer layer 95 between the bottom-most over-passivation metallayer 801 and the passivation layer 5 planarizes the surface of thepassivation layer 5, and decouples the over-passivation metal scheme 80from the underlying fine-line metal scheme 6, resulting in highelectrical performance. In some applications, the polymer layer 95 maybe omitted to for cost saving. Note that openings 950 are aligned withthe passivation openings 50. Note also that the polymer openings 950 canbe either larger or smaller than the passivation openings 50. As analternative, regards to the starting material of the conventionalfinished IC chip 10 in FIG. 15A, there are no openings in thepassivation layer 5, next the polymer layer 95 is spin coated on thepassivation layer 5, followed by forming the openings 950 in the polymerlayer 95 exposing the passivation layer 5, and then forming the openings50 in the passivation layer 5 under the openings 950, exposing thecontact pads of the fine-line metal scheme 6. In this option, thepolymer openings 950 are about the same size as the openings 50 in thepassivation layer 5.

FIGS. 15D-15H show an embossing process to form the firstover-passivation metal layer 801 shown in FIG. 15K. Referring to FIG.15D, an adhesio/barrier/seed layer 8011 is deposited, preferred bysputtering, on the polymer layer 95 and on the metal pads 600 exposed bythe openings 950. For the gold metal system, the adhesion/barrier/seedlayer 8011 can be formed by sputtering a titanium layer, acting as anadhesion/barrier layer, having a thickness of between 0.02 and 0.8 μm,and preferably of 3,000 Å, on the polymer layer 95 and on the metal pads600, such as aluminum pads or copper pads, exposed by the openings 950,followed by sputterin a seed layer, made of gold, having a thickness ofbetween 0.005 and 0.7 μm, and preferably of 1,000 Å, on the titaniumlayer. Alternatively, for the gold metal system, theadhesion/barrier/seed layer 8011 can be formed by sputtering atitanium-tungsten-alloy layer layer, acting as an adhesion/barrierlayer, having a thickness of between 0.02 and 0.8 μm, and preferably of3,000 Å, on the polymer layer 95 and on the metal pads 600, such asaluminum pads or copper pads, exposed by the openings 950, followed bysputterin a seed layer, made of gold, having a thickness of between0.005 and 0.7 μm, and preferably of 1,000 Å, on thetitanium-tungsten-alloy layer. For the copper metal system, theadhesion/barrier/seed layer 8011 can be formed by sputtering a chromiumlayer, acting as an adhesion/barrier layer, having a thickness ofbetween 0.02 and 0.8 μm, and preferably of 500 Å, on the polymer layer95 and on the metal pads 600, such as aluminum pads or copper pads,exposed by the openings 950, followed by sputterin a seed layer, made ofcopper, having a thickness of between 0.005 and 0.7 μm, and preferablyof 5,000 Å, on the chromium layer. Alternatively, for the copper metalsystem, the adhesion/barrier/seed layer 8011 can be formed by sputteringa titanium layer, acting as an adhesion/barrier layer, having athickness of between 0.02 and 0.8 μm, and preferably of 1,000 Å, on thepolymer layer 95 and on the metal pads 600, such as aluminum pads orcopper pads, exposed by the openings 950, followed by sputterin a seedlayer, made of copper, having a thickness of between 0.005 and 0.7 μm,and preferably of 5,000 Å, on the titanium layer. Alternatively, for thecopper metal system, the adhesion/barrier/seed layer 8011 can be formedby sputtering a titanium-tungsten-alloy layer, acting as anadhesion/barrier layer, having a thickness of between 0.02 and 0.8 μm,and preferably of 3,000 Å, on the polymer layer 95 and on the metal pads600, such as aluminum pads or copper pads, exposed by the openings 950,followed by sputterin a seed layer, made of copper, having a thicknessof between 0.005 and 0.7 μm, and preferably of 5,000 Å, on thetitanium-tungsten-alloy layer.

FIG. 15E shows a photoresist layer 71 is deposited and patterned on theseed layer of the adhesion/barrier/seed layer 8011. The photoresistlayer 71 is spin-on coated, exposed by an aligner or a 1× stepper, anddeveloped to form openings 710 in the photoresist layer 71. The openings710 defined the metal lines, traces or planes to be formed in thesubsequent process, and contacts in the polymer openings 950 and thepassivation openings 50. The contacts are over and connected to theexposed fine-line metal pads 600.

For example, the photoresist layer 71 can be formed by spin-on coating apositive-type photosensitive polymer layer on the seed layer of theadhesion/barrier/seed layer 8011, then exposing the photosensitivepolymer layer using a 1× stepper or 1× contact aligner with at least twoof G-line having a wavelength ranging from 434 to 438 nm , H-line havinga wavelength ranging from 403 to 407 nm, and I-line having a wavelengthranging from 363 to 367 nm, illuminating the photosensitive polymerlayer, that is, G-line and H-line, G-line and I-line, H-line and I-line,or G-line, H-line and I-line illuminate the photosensitive polymerlayer, then developing the exposed polymer layer, and then removing theresidual polymeric material or other contaminants from the seed layerwith an O₂ plasma or a plasma containing fluorine of below 200 PPM andoxygen, such that the photoresist layer 71 can be patterned withopenings 710 exposing the seed layer of the adhesion/barrier/seed layer8011.

Referring to FIG. 15F, a bulk conduction metal layer 8012 can beelectroplated and/or electroless plated over the seed layer, exposed bythe openings 710 in the photoresist layer 71, of theadhesion/barrier/seed layer 8011. The bulk conduction metal layer 8012may be a single layer of gold, copper, silver, palladium, platinum,rhodium, ruthenium, rhenium or nickel, or a composite layer made of theabove mentioned metals. For example, the bulk conduction metal layer8012 can be a gold layer with a thickness between 2 and 50 μm, preferredbetween 2 and 30 μm. Alternatively, the bulk conduction metal layer 8012can be a copper layer with a thickness between 2 and 200 μm, preferredbetween 2 and 30 μm.

For example, the bulk conduction metal layer 8012 may be formed byelectroplating a gold layer with a thickness of between 2 and 50 μm, andpreferably of between 2 and 30 μm, on the seed layer, made of gold,exposed by the openings 710. Alternatively, the bulk conduction metallayer 8012 may be formed by electroplating a copper layer with athickness of between 2 and 200 μm, and preferably of between 2 and 30μm, on the seed layer, made of copper, exposed by the openings 710.Alternatively, the bulk conduction metal layer 8012 may be formed byelectroplating a copper layer with a thickness of between 2 and 30 μm,and preferably of between 3 and 15 μm, on the seed layer, made ofcopper, exposed by the openings 710, and then electroplating a goldlayer with a thickness of between 0.5 and 10 μm on the copper layer inthe openings 710. Alternatively, the bulk conduction metal layer 8012may be formed by electroplating a copper layer with a thickness ofbetween 2 and 30 μm, and preferably of between 3 and 15 μm, on the seedlayer, made of copper, exposed by the openings 710, then electroplatinga nickel layer with a thickness of between 0.5 and 5 μm, and preferablyof between 1 and 3 μm, on the copper layer in the openings 710, and thenelectroplating a gold layer with a thickness of between 0.03 and 0.5 μm,and preferably of between 0.05 and 0.1 μm, on the nickel layer in theopenings 710. Alternatively, the bulk conduction metal layer 8012 may beformed by electroplating a copper layer with a thickness of between 2and 30 μm, and preferably of between 3 and 15 μm, on the seed layer,made of copper, exposed by the openings 710, then electroplating anickel layer with a thickness of between 0.5 and 5 μm, and preferably ofbetween 1 and 3 μm, on the copper layer in the openings 710, and thenelectroless plating a gold layer with a thickness of between 0.03 and0.5 μm, and preferably of between 0.05 and 0.1 μm, on the nickel layerin the openings 710. Alternatively, the bulk conduction metal layer 8012may be formed by electroplating a copper layer with a thickness ofbetween 2 and 30 μm, and preferably of between 3 and 15 μm, on the seedlayer, made of copper, exposed by the openings 710, then electroplatinga nickel layer with a thickness of between 0.5 and 5 μm, and preferablyof between 1 and 3 μm, on the copper layer in the openings 710, and thenelectroplating a palladium layer with a thickness of between 0.03 and0.5 μm, and preferably of between 0.05 and 0.1 μm, on the nickel layerin the openings 710. Alternatively, the bulk conduction metal layer 8012may be formed by electroplating a copper layer with a thickness ofbetween 2 and 30 μm, and preferably of between 3 and 15 μm, on the seedlayer, made of copper, exposed by the openings 710, then electroplatinga nickel layer with a thickness of between 0.5 and 5 μm, and preferablyof between 1 and 3 μm, on the copper layer in the openings 710, and thenelectroless plating a palladium layer with a thickness of between 0.03and 0.5 μm, and preferably of between 0.05 and 0.1 μm, on the nickellayer in the openings 710. Alternatively, the bulk conduction metallayer 8012 may be formed by electroplating a copper layer with athickness of between 2 and 30 μm, and preferably of between 3 and 15 μm,on the seed layer, made of copper, exposed by the openings 710, thenelectroplating a nickel layer with a thickness of between 0.5 and 5 μm,and preferably of between 1 and 3μm, on the copper layer in the openings710, and then electroplating a platinum layer with a thickness ofbetween 0.03 and 0.5 μm, and preferably of between 0.05 and 0.1 μm, onthe nickel layer in the openings 710. Alternatively, the bulk conductionmetal layer 8012 may be formed by electroplating a copper layer with athickness of between 2 and 30 μm, and preferably of between 3 and 15 μm,on the seed layer, made of copper, exposed by the openings 710, thenelectroplating a nickel layer with a thickness of between 0.5 and 5 μm,and preferably of between 1 and 3 μm, on the copper layer in theopenings 710, and then electroless plating a platinum layer with athickness of between 0.03 and 0.5 μm, and preferably of between 0.05 and0.1 μm, on the nickel layer in the openings 710.

A cap/barrier layer (not shown) can be optionally formed byelectroplating or electroless plating over the bulk conduction metallayer 8012. An assembly/contact layer (not shown) can also be furtherformed, as an option also, over the bulk conduction metal layer 8012 andthe cap/barrier layer by electroplating or electroless plating. Theassembly/contact layer can be a Au, Pd or Ru layer with thicknessbetween 0.01 and 5 μm.

Referring to FIG. 15G, the phoresist layer 71 is then stripped using anorganic solution with amide. However, some residuals from thephotoresist layer 71 could remain on the bulk conduction metal layer8012 and on the seed layer of the adhesion/barrier/seed layer 8011.Thereafter, the residuals can be removed from the bulk conduction metallayer 8012 and from the seed layer of the adhesion/barrier/seed layer8011 with a plasma, such as O₂ plasma or plasma containing fluorine ofbelow 200 PPM and oxygen.

Referring to FIG. 15H, the adhesion/barrier/seed layer 8011 not underthe bulk conduction metal layer 8012 is then removed by self-aligned wetand/or dry etching. In the case of wet etching to remove the bottommetal layer 8011 not under the electrplated metal layer 8012, anundercut 8011′ with a sidewall of the bottom metal layer 8011 recessedfrom a sidewall of the electroplated metal layer 8012 is formed. Noundercut 8011′ exists when an anisotropies dry etching is used to removethe bottom metal layer 8011 not under the electroplated metal layer8012.

For example, when the seed layer of the adhesion/barrier/seed layer 8011is a gold layer, it can be etched with an iodine-containing solution,such as solution containing potassium iodide, with an ion millingprocess or with an Ar sputtering etching process. Alternatively, whenthe seed layer of the adhesion/barrier/seed layer 8011 is a copperlayer, it can be etched with a solution containing NH₄OH or with an Arsputtering etching process.

For example, when the adhesion/barrier layer of theadhesion/barrier/seed layer 8011 is a titanium-tungsten-alloy layer, itcan be etched with a solution containing hydrogen peroxide, with achlorine-containing plasma etching process or with an RIE process.Alternatively, when the adhesion/barrier layer of theadhesion/barrier/seed layer 8011 is a titanium layer, it can be etchedwith a solution containing hydrogen fluoride, with a chlorine-containingplasma etching process or with an RIE process. Alternatively, when theadhesion/barrier layer of the adhesion/barrier/seed layer 8011 is achromium layer, it can be etched with a solution containing potassiumferricyanide.

FIGS. 15I and 15J show repeated process of FIGS. 15C-15H to form thesecond polymer layer 98 and the second metal layer 802, that is, apolymer layer 98 is formed on the polymer layer 95 and on the firstmetal layer 801, openings 980 in the polymer layer 98 exposing the bulkconduction metal layer 8012 of the first metal layer 801, followed byforming an adhesion/barrier layer of an adhesion/barrier/seed layer 8021on the polymer layer 98 and on the bulk conduction metal layer 8012exposed by the polymer openings 980, followed by forming a seed layer ofthe adhesion/barrier/seed layer 8021 on the adhesion/barrier layer,followed by forming a pohotresist layer on the seed layer, openings inthe photoresist layer exposing the seed layer, followed by forming abulk conduction metal layer 8022 on the seed layer exposed by theopenings in the photoresist layer, followed by removing the photoresistlayer, followed by removing the adhesion/barrier/seed layer 8021 notunder the bulk conduction metal layer 8022. The specification of thepolymer layer 98, the adhesion/barrier/seed layer 8021 and the bulkconduction metal layer 8022 shown in FIGS. 15I-15L can be referred to asthe specification of the polymer layer 95, the adhesion/barrier/seedlayer 8011 and the bulk conduction metal layer 8012 illustrated in FIGS.15C-15H, respectively. The process of forming the polymer layer 98 shownin FIGS. 15I-15J can be referred to as the process of forming thepolymer layer 95 illustrated in FIGS. 15C-15H. The process of formingthe adhesion/barrier/seed layer 8021 shown in FIGS. 15I-15J can bereferred to as the process of forming the adhesion/barrier/seed layer8011 illustrated in FIGS. 15C-15H. The process of forming the bulkconduction metal layer 8022 shown in FIGS. 15I-15J can be referred to asthe process of forming the bulk conduction metal layer 8012 illustratedin FIGS. 15C-15H.

Processes in FIGS. 15I and 15J can be repeated for the third, fourth,and/or more metal layers. Referring to FIG. 15K, if the over-passivationscheme 8 comprises two metal layers 801 and 802, a cap polymer layer 99is deposited on the second (now the top-most) over-passivation metallayer 802 and on the second polymer layer 98 not covered by the metallayer 802. Openings 990 are formed in the cap polymer layer 99 to exposeover-passivation contact pads 8000 for connecting to external circuits.In some applications, for example, in the Au over-passivation metalsystem used for the topmost patterned circuit layer 802, the cap polymerlayer 99 may optionally be omitted. FIG. 15K shows an IC chip with boththe fine-line metal system 6 and the over-passivation metal system 8,with the contact pads 8000 exposed by the openings 990 in the cappolymer layer 99.

The wafer is sawed (diced) into separated chips. The contact pads 8000of the separated chips can be used for connecting to the externalcircuits by (1) wires (such as gold wires, aluminum wires or copperwires) of a wirebonding process; (2) bumps (such as gold bumps, copperbumps, solder bumps or other metal bumps) on the other substrates (suchas silicon chips, silicon substrates, ceramic substrates, organicsubstrates, BGA substrates, flexible substrates, flexible tapes or glasssubstrates). The bumps on the substrates have a height between 1 and 30μm, preferred between 5 and 20 μm; (3) posts (such as gold posts, copperposts, solder posts or other metal posts) on the other substrates (suchas silicon chips, silicon substrates, ceramic substrates, organicsubstrates, BGA substrates, flexible substrates, flexible tapes or glasssubstrates). The posts on the substrates have a height between 10 and200 μm, preferred between 30 and 120 μm; (4) bumps (such as gold bumps,copper bumps, solder bumps or other metal bumps) on the terminals ofmetal leads of a lead-frames or a flexible tape. The bumps on the metalleads have a height between 1 and 30 μm, preferred between 5 and 20 μm.

In some other applications, a contact structure 89 is formed over thecontact pad 8000 for connection to external circuits, as shown in FIG.15L. An adhesion/barrier layer 891 is formed under the contact structure89 for adhesion and diffusion barrier purposes. The contact structure 89can be (1) solder pads (with a thickness between 0.1 μm and 30 μm,preferred between 1 μm and 10 μm).or solder bumps (with a height between10 μm and 200 μm, preferred between 30 μm and 120 μm) formed byelectroplating, or screen printing. A solder reflow process is requiredto form a ball-shaped solder ball. Solder pads or bumps comprise highlead solder (PbSn, with Pb composition greater than 85 % weightpercentage), eutectic solder (PbSn, with −37% Pb weight percentage, and−63% Sn weight percentage), or lead-free solder comprising SnAg, orSnCuAg. The adhesion/barrier layer 891 under the solder pads or solderbumps 89 comprise a composite layer of Ti/Ni, Ti/Cu/Ni, TiW/Ni,TiW/Cu/Ni, Ti/Ni/Au, Ti/Cu/Ni/Au, TiW/Ni/Au, TiW/Cu/Ni/Au, Ti/Cu/Ni/Pd,TiW/Cu/Ni/Pd, Cr/CrCu, NiV/Cu, NiV/Cu, NiV/Au, Ni/Au, Ni/Pd, all layersare from bottom to top; (2) gold pads (with a thickness between 0.1 μmand 10 μm, preferred between 1 μm and 5 μm) or gold bumps (with a heightbetween 5 μm and 40 μm, preferred between 10 μm and 20 μm) formed byelectroplating. An adhesion/barrier layer 891 under the gold pads orgold bumps 89 comprises a composite layer of Ti, TiW, Ta, TaN, Ti/Cu/Ni,TiW/Cu/Ni, all layers are from bottom to top; (3) metal balls formed byball mounting. The metal ball can be a solder ball, a copper ball withsurface coating of a Ni layer, or a copper ball with surface coating ofa Ni layer and a solder layer, or a copper ball with surface coating ofa Ni alyer and a gold layer. A diameter of the metal ball is between 10μm and 500 μm, preferred between 50 μm and 3000 μm. A metal ball can bemounted directly on the surface of the metal pad 8000 exposed by thepolymer opening 990, or on the UBM (Under Bump Metal) layer 891. The UBMlayer 891 formed for the metal ball mounting comprises a composite layerof Ti/Ni, Ti/Cu/Ni, TiW/Ni, TiW/Cu/Ni, Ti/Ni/Au, Ti/Cu/Ni/Au, TiW/Ni/Au,TiW/Cu/Ni/Au, Ti/Cu/Ni/Pd, TiW/Cu/Ni/Pd, Cr/CrCu, NiV/Cu, NiV/Cu,NiV/Au, Ni/Au, Ni/Pd, all layers are from bottom to top. After the metalball mounting, a solder reflow process is usually required. Afterforming the contact structure 89, the chips on the wafer are separatedby sawing or dicing for packaging or assembly to connect to externalcircuits. The assembly methods can be wirebonding (to pads on externalorganic, ceramic, glass, or silicon substrates, or to leads of aleadframe or a flexible tape), TAB bonding, tape-chip-carrier packaging(TCP), chip-on-glass (COG), chip-on-board (COB), chip-on-film (COF),flip chip on a BGA substrate, chip-on-flex, chip-on-chip stackinterconnection or chip-on-Si-substrate stack interconnection.

The emboss process shown in FIGS. 15C to 15K describes a metal layer isformed by only one photoresist patterning process for electroplating ametal layer in an opening in the only one photoresist layer. This typeof process is a single-emboss process that means the process comprisesone and only one photolithography process before removing theadhesion/barrier/seed layer not under the electroplated metal layer. Adouble-emboss process can be implemented to form a metal trace and a viaplug on the metal trace by electroplating metal layers with differentpatterns using only one adhesion/barrier/seed layer, while performingtwo photolithography precesses, before removing theadhesion/barrier/seed layer not under an electroplated metal layer. Thefirst photolithgrphy process is performed for defining the pattern ofthe metal trace, while the second photolithography process is performedfor defining the pattern of the via plug. FIGS. 15C-15G and FIGS.16A-16D show the double-embossing process to form the over-passivationscheme 8 over the conventional IC chip 10 shown in FIG. 15A or FIG. 15B.The double-embossing process has front steps same as the steps shown inFIGS. 15C-15G. The steps of FIGS. 16A-16D follow the steps of FIGS.15C-15G for a double embossing process. In FIG. 15G, the photoresistlayer 71 is stripped, leaving the adhesion/barrier/seed layer 8011 notunder the bulk conduction metal layer 8012 exposed to the ambient. FIGS.16A-16L show an example to form an over-passivation scheme 8 for allembodiments in this invention by using a double-embosising process toform the first metal layer 801 and via plugs 898, and using a singleembossing to form the top-most metal layer 802.

FIGS. 15D-15G, a first phtolithograpgy and electroplating process isperformed to form the first metal layer 801. Starting with the structurein FIG. 15C; a second photoresist layer 72 is deposited and patterned onthe seed layer of the adhesion/barrier/seed layer 8011 and on theelectroplated bulk conduction metal layer 8012, as shown in FIG. 16A. Itis noted that openings 720 in the photoresist layer 72 expose the bulkconduction metal layer 8012; openings 720′ in the photoresist layer 72expose the seed layer of the adhesion/barrier/seed layer 8011.

For example, the photoresist layer 72 can be formed by spin-on coating apositive-type photosensitive polymer layer on the seed layer of theadhesion/barrier/seed layer 8011 and on the electroplated bulkconduction metal layer 8012, then exposing the photosensitive polymerlayer using a 1× stepper or 1× contact aligner with at least two ofG-line having a wavelength ranging from 434 to 438 nm , H-line having awavelength ranging from 403 to 407 nm, and I-line having a wavelengthranging from 363 to 367 nm, illuminating the photosensitive polymerlayer, that is, G-line and H-line, G-line and I-line, H-line and I-line,or G-line, H-line and I-line illuminate the photosensitive polymerlayer, then developing the exposed polymer layer, and then removing theresidual polymeric material or other contaminants from the seed layerand form the bulk conduction metal layer 8012 with an O₂ plasma or aplasma containing fluorine of below 200 PPM and oxygen, such that thephotoresist layer 72 can be patterned with the openings 720 and 720′exposing the bulk conduction metal layer 8012 and the seed layer of theadhesion/barrier/seed layer 8011, respectively.

Referring to FIG. 16B, since the seed layer of the adhesion/barrier/seedlayer 8011 is not removed, a second electroplating process can beperformed to form via plugs 898. Note that a metal piece 898′ on theseed layer of the adhesion/barrier/seed layer 8011 is also formed at ahorizontal level lower than via plugs 898. The metal piece 898′ can beused for packaging purposes. The metal piece 898′ may be thinner orthicker than the bulk conduction metal layer 8012. It can be used forhigher density interconnection (in case of thinner) or used for lowerresistance interconnection (in case of thicker).

The material of the via plug 898 and metal piece 898′ may be gold orcopper. For example, the via plug 898 and metal piece 898′ may be formedby electroplating a gold layer with a thickness of between 1 and 100 μm,and preferably of between 2 and 30 μm, on the gold layer, exposed by theopenings 720, of the bulk conduction metal layer 8012, and on the seedlayer, made of gold, of the adhesion/barrier/seed layer 8011 exposed bythe openings 720′. Alternatively, the via plug 898 and metal piece 898′may be formed by electroplating a copper layer with a thickness ofbetween 1 and 100 μm, and preferably of between 2 and 30 μm, on thecopper layer, exposed by the openings 720, of the bulk conduction metallayer 8012, and on the seed layer, made of copper, of theadhesion/barrier/seed layer 8011 exposed by the openings 720′.

Referring to FIG. 16C, the second photoresist 72 is then removed usingan organic solution with amide, exposing the via plugs 898, the bulkconduction metal layer 8012 not under the via plugs 898, the seed layerof the adhesion/barrier/seed layer 8011 not under the bulk conductionmetal layer 8012, and the metal piece 898′. However, some residuals fromthe photoresist layer 72 could remain on the bulk conduction metal layer8012 and on the seed layer of the adhesion/barrier/seed layer 8011.Thereafter, the residuals can be removed from the seed layer of theadhesion/barrier/seed layer 8011 and from the bulk conduction metallayer 8012 with a plasma, such as O₂ plasma or plasma containingfluorine of below 200 PPM and oxygen.

Referring to FIG. 16D, the adhesion/barrier/seed layer 8011 not underthe bulk conduction metal layer 8012 and not under the metal piece 898′is removed by wet and/or dry etching. In the case of wet etching toremove the bottom metal layer 8011 not under the electroplated metallayer 8012 and not under the electroplated metal layer 898, an undercut8011′ with a sidewall of the bottom metal layer 8011 recessed from asidewall of the electroplated metal layer 8012 and with a sidewall ofthe bottom metal layer 8011 recessed from a sidewall of theelectroplated metal layer 898′ is formed. No undercut 8011′ exists whenan anisotropies dry etching is used to remove the bottom metal layer8011 not under the electroplated metal layer 8012 and not under theelectroplated metal layer 898′.

For example, when the seed layer of the adhesion/barrier/seed layer 8011is a gold layer, it can be etched with an iodine-containing solution,such as solution containing potassium iodide, with an ion millingprocess or with an Ar sputtering etching process. Alternatively, whenthe seed layer of the adhesion/barrier/seed layer 8011 is a copperlayer, it can be etched with a solution containing NH₄OH or with an Arsputtering etching process.

For example, when the adhesion/barrier layer of theadhesion/barrier/seed layer 8011 is a titanium-tungsten-alloy layer, itcan be etched with a solution containing hydrogen peroxide, with achlorine-containing plasma etching process or with an RIE process.Alternatively, when the adhesion/barrier layer of theadhesion/barrier/seed layer 8011 is a titanium layer, it can be etchedwith a solution containing hydrogen fluoride, with a chlorine-containingplasma etching process or with an RIE process. Alternatively, when theadhesion/barrier layer of the adhesion/barrier/seed layer 8011 is achromium layer, it can be etched with a solution containing potassiumferricyanide.

Referring to FIG. 16E, a second polymer layer 98 is deposited on the viaplugs 898, on the metal pieces 898′, on the metal layer 801 and on theexposed first polymer layer 95. The second polymer layer 98 can beformed by a spin-on coating process, a lamination process or ascreen-printing process.

For example, the polymer layer 98 can be formed by spin-on coating anegative-type photosensitive polyimide layer, containing ester-typerprecursor, having a thickness of between 6 and 50 μm on the via plugs898, on the metal pieces 898′, on the bulk conduction metal layer 8012and on the exposed polymer layer 95, then baking the spin-on coatedpolyimide layer, and then curing or heating the baked polyimide layer ata peak temperature of between 290 and 400° C. for a time of between 20and 150 minutes in a nitrogen ambient or in an oxygen-free ambient, thecured polyimide layer having a thickness of between 3 and 25 μm.Alternatively, the baked polyimide layer can be cured or heated at atemperature between 150 and 290° C., and preferably of between 260 and280° C., for a time of between 20 and 150 minutes in a nitrogen ambientor in an oxygen-free ambient.

Referring to FIG. 16F, a polishing or mechanical polishing process, andpreferably a chemical-mechanical polishing (CMP) process, is used toplanarize the surface of the second polymer layer 98, exposing the viaplugs 898. The polymer layer 98, after being planarized, may have athickness t between 5 and 50 micrometers.

FIGS. 16G-16K show process steps to form a second over-passivation metallayer 802 using a single-embossing process same as described in FIGS.15D-15H, that is, an adhesion/barrier/seed layer 8021 is deposited,preferred by sputtering, on the second polymer layer 98 and on theexposed via plugs 898, followed by forming a photoresist layer 73 on theadhesion/barrier/seed layer 8021, openings 730 in the photoresist layer73 exposing the seed layer of the adhesion/barrier/seed layer 8021,followed by forming a bulk conduction metal layer 8022 on the seed layerexposed by the openings 730, followed by removing the photoresist layer73, followed by removing the adhesion/barrier/seed layer 8021 not underthe bulk conduction metal layer 8022. The specification of theadhesion/barrier/seed layer 8021 and the bulk conduction metal layer8022 shown in FIGS. 16G-16K can be referred to as the specification ofthe adhesion/barrier/seed layer 8011 and the bulk conduction metal layer8012 illustrated in FIGS. 15D-15K, respectively. The process of formingthe adhesion/barrier/seed layer 8021 shown in FIGS. 16G-16K can bereferred to as the process of forming the adhesion/barrier/seed layer8011 illustrated in FIGS. 15D-15K. The process of forming the bulkconduction metal layer 8022 shown in FIGS. 16G-16K can be referred to asthe process of forming the bulk conduction metal layer 8012 illustratedin FIGS. 15D-15K.

Referring to FIG. 16L, a cap layer 99 is then deposited and patterned tocomplete a two-metal-layer over-passivation scheme 8. A contactstructure 89 illustrated in FIG. 15L can be formed on the exposed metalpad 8000 shown in FIG. 16L for assembly and/or packaging purposes. Thespecification of the contact structure 89 shown in FIG. 16L can bereferred to as the specification of the contact structure 89 illustratedin FIG. 15L. The process of forming the contact structure 89 shown inFIG. 16L can be referred to as the process of forming the contactstructure 89 illustrated in FIG. 15L. As an alternative, thedouble-emboss process steps in FIGS. 15D-15G and 16A-16D for forming thefirst metal layer 801 and the first via plug 898 can be repeated to formadditional metal layer (not shown) on the polymer layer 98 and on thevia plugs 898, and to form additional via plug (not shown) on theadditional metal layer. In this alternative, the additional via plug canbe joined with a wirebonded wire using a wirebonding process, with asolder bump using a ball-mounting process or with a flexible substrateusing a TAB process. The description and specification in FIGS. 16A-16Lcan be applied to forming the thick and wide power metal trace, bus orplane 81 over the passivation layer 5 in the first embodiment, toforming the thick and wide ground metal trace, bus or plane 82 over thepassivation layer 5 in the first and fourth embodiments, to forming thethick and wide power metal trace, bus or plane 81P over the passivationlayer 5 in the first and fourth embodiments, and to forming the thickand wide signal metal trace, bus or plane 83, 83′ or 85 over thepassivation layer 5 in the second and third embodiments.

FIGS. 17A to 17J show process steps to form an over-passivation scheme 8with three metal layers 801, 802 and 803. Metal layers 801 and 802 areformed by a double-emboss process, while the metal layer 803 is formedby a single-emboss process. A first double-embossing process is used toform the first metal layer 801 and the first via plug 898 as describedin FIGS. 15D-15G and 16A-16D. A first inter-metal polymer layer 98 isformed and planarized to expose the first via plugs 898, shown inprocess steps of FIGS. 16E-16F. FIG. 17A is at the same step as FIG. 16Jwhen the first metal layer 801, the first via plugs 898 and the metalpiece 898′ are formed by a double-emboss metal process, and theinter-metal dilectric polymer layer 98 is formed with the first viaplugs 898 being exposed. The design of the first metal layer 801 and thefirst via plugs 898 in FIG. 17A is slightly different from that in FIG.16J to accommodate an additional metal layer. The process for formingthe bottom metal layer 8021 in FIG. 17A can be referred to as theprocess for forming the bottom metal layer 8011 in FIG. 15D or thebottom metal layer 8021 in FIG. 16G; the process for forming the metallayer 8022 in FIG. 17A can be referred to as the process for forming themetal layer 8012 in FIG. 15E or the metal layer 8022 in FIGS. 16H-16J.The specification of the adhesion/barrier/seed layer 8021 and the bulkconduction metal layer 8022 shown in FIGS. 17A-17J can be referred to asthe specification of the adhesion/barrier/seed layer 8011 and the bulkconduction metal layer 8012 illustrated in FIGS. 15D-15K, respectively.Referring to FIG. 17B now, a second photoresist layer 74 is thendeposied and patterned to form openings 740 over the bulk conductionmetal layer 8022 and/or to optionally form openings 740′ directly on theseed layer of the second adhesion/barrier/seed layer 8021.

For example, the photoresist layer 74 can be formed by spin-on coating apositive-type photosensitive polymer layer on the seed layer of theadhesion/barrier/seed layer 8021 and on the bulk conduction metal layer8022, then exposing the photosensitive polymer layer using a 1× stepperor 1× contact aligner with at least two of G-line having a wavelengthranging from 434 to 438 nm , H-line having a wavelength ranging from 403to 407 nm, and I-line having a wavelength ranging from 363 to 367 nm,illuminating the photosensitive polymer layer, that is, G-line andH-line, G-line and I-line, H-line and I-line, or G-line, H-line andI-line illuminate the photosensitive polymer layer, then developing theexposed polymer layer, and then removing the residual polymeric materialor other contaminants from the seed layer and form the bulk conductionmetal layer 8022 with an O₂ plasma or a plasma containing fluorine ofbelow 200 PPM and oxygen, such that the photoresist layer 74 can bepatterned with the openings 740 and 740′ exposing the bulk conductionmetal layer 8022 and the seed layer of the adhesion/barrier/seed layer8021, respectively.

Referring to FIG. 17C, a second via plug layer is electroplated in thephotoresist openings 740 and 740′ to form the second via plugs 897 andthe second metal piece 897′. The second metal piece 897′ can be used asdescribed for the first metal piece 989′. The material of the via plug897 and metal piece 897′ may be gold or copper. For example, the viaplug 897 and metal piece 897′ may be formed by electroplating a goldlayer with a thickness of between 1 and 100 μm, and preferably ofbetween 2 and 30 μm, on the gold layer, exposed by the openings 740, ofthe bulk conduction metal layer 8022, and on the seed layer, made ofgold, of the adhesion/barrier/seed layer 8021 exposed by the openings740′. Alternatively, the via plug 897 and metal piece 897′ may be formedby electroplating a copper layer with a thickness of between 1 and 100μm, and preferably of between 2 and 30 μm, on the copper layer, exposedby the openings 740, of the bulk conduction metal layer 8022, and on theseed layer, made of copper, of the adhesion/barrier/seed layer 8021exposed by the openings 740′.

Referring to FIG. 17D, the second photoresist layer 74 is then strippedusing an organic solution with amide. However, some residuals from thephotoresist layer 74 could remain on the bulk conduction metal layer8022 and on the seed layer of the adhesion/barrier/seed layer 8021.Thereafter, the residuals can be removed from the bulk conduction metallayer 8022 and from the seed layer with a plasma, such as O₂ plasma orplasma containing fluorine of below 200 PPM and oxygen.

Alternatively, after the bulk conduction metal layer 8022 is formed onthe seed layer of the adhesion/barrier/seed layer 8021 exposed by theopenings 730 illustrated in FIG. 161, without removing the photoresistlayer 73, the photoresist layer 74 shown in FIG. 17B can be formed onthe photoresist layer 73 and on the bulk conduction metal layer 8022.The openings 740 in the photoresist layer 74 expose the bulk conductionmetal layer 8022, respectively, for defining the pattern of the viaplugs 897. The process for forming the via plugs 897 can be referred toas the above disclosure. Finally, the photoresist layers 73 and 74 areremoved using an organic solution with amide. However, some residualsfrom the photoresist layers 73 and 74 could remain on the bulkconduction metal layer 8022, on the via plugs 897 and on the seed layerof the adhesion/barrier/seed layer 8021. Thereafter, the residuals canbe removed from the seed layer of the adhesion/barrier/seed layer 8021,from the via plugs 897 and from the bulk conduction metal layer 8022with a plasma, such as O₂ plasma or plasma containing fluorine of below200 PPM and oxygen. Next, the adhesion/barrier/seed layer 8021 not underthe bulk conduction metal layer 8022 can be removed, as mentioned in theabove description. Referring to FIG. 17E, the secondadhesion/barrier/seed layer 8021 not under the second bulk conductionmetal layer 8022 and not under the second metal piece 987′ is removed.The process of removing the second adhesion/barrier/seed layer 8021 notunder the second bulk conduction metal layer 8022 and not under thesecond metal piece 897′, as shown in FIG. 17E, can be referred to as theprocess of removing the first adhesion/barrier/seed layer 8011 not underthe first bulk conduction metal layer 8012 and not under the metal piece898′, as illustrated in FIG. 16D.

Referring to FIGS. 17F-17G, a second inter-metal dielectric polymerlayer 97 is then deposited and planarized to expose the second via plugs897. The material of the polymer layer 97 may be polyimide (PI),benzocyclobutane (BCB), polyurethane, epoxy resin, a parylene-basedpolymer, a solder-mask material, an elastomer, silicone or a porousdielectric material. The process for forming the polymer layer 97 inFIG. 17F can be as referred to as the process for forming the polymerlayer 98 in FIG. 16E; the process for planarizing the polymer layer 97in FIG. 17G can be as referred to as the process for planarizing thepolymer layer 98 in FIG. 16F.

For example, the polymer layer 97 can be formed by spin-on coating anegative-type photosensitive polyimide layer, containing ester-typerprecursor, having a thickness of between 10 and 120 μm on the exposedbulk conduction metal layer 8022, on the via plugs 897, on the metalpiece 897′ and on the exposed polymer layer 98, then baking the spin-oncoated polyimide layer, then curing or heating the baked polyimide layerat a peak temperature of between 290 and 400° C. for a time of between20 and 150 minutes in a nitrogen ambient or in an oxygen-free ambient,the cured polyimide layer having a thickness of between 5 and 60 μm, andthen polishing or mechanical polishing, preferred chemical-mechanicalpolishing, an upper surface of the polymer layer 97 to uncover the viaplugs 897 and to planarize the upper surface thereof. Alternatively, thebaked polyimide layer can be cured or heated at a temperature between150 and 290° C., and preferably of between 260 and 280° C., for a timeof between 20 and 150 minutes in a nitrogen ambient or in an oxygen-freeambient.

FIGS. 17H and 171 show a single-embossing process is used to form athird metal layer 803 by first depositing an adhesion/barrier/seeddlayer 8031, depositing and patterning a photoresist layer,electroplating a bulk conduction metal layer 8032, stripping thephotoresist layer and self-aligned etch the adhesion/barrier/seed layer8031. The specification of the adhesion/barrier/seed layer 8031 and thebulk conduction metal layer 8032 shown in FIGS. 17H-17I can be referredto as the specification of the adhesion/barrier/seed layer 8011 and thebulk conduction metal layer 8012 illustrated in FIGS. 15D-15H,respectively. The process of forming the adhesion/barrier/seed layer8031 shown in FIGS. 17H-17I can be referred to as the process of formingthe adhesion/barrier/seed layer 8011 illustrated in FIGS. 15D-15H. Theprocess of forming the bulk conduction metal layer 8032 shown in FIGS.17H-17I can be referred to as the process of forming the bulk conductionmetal layer 8012 illustrated in FIGS. 15D-15H.

FIG. 17J shows a completed structure by depositing and pattern a cappolymer layer 99 on the exposed polymer layer 97 and on the third metallayer 803, an opening 990 in the cap polymer layer 99 exposing a contactpad 8000 for interconnection to an external circuit.

The polymer layer 99 may be formed by a spin-on coating process, alamination process or a screen-printing process. The material of thepolymer layer 99 may be polyimide (PI), benzocyclobutane (BCB),polyurethane, epoxy resin, a parylene-based polymer, a solder-maskmaterial, an elastomer, silicone or a porous dielectric material.

For example, the polymer layer 99 can be formed by spin-on coating anegative-type photosensitive polyimide layer, containing ester-typerprecursor, having a thickness of between 6 and 50 μm on the exposedpolymer layer 97 and on the bulk conduction metal layer 8032, thenbaking the spin-on coated polyimide layer, then exposing the bakedpolyimide layer using a 1× stepper or 1× contact aligner with at leasttwo of G-line having a wavelength ranging from 434 to 438 nm , H-linehaving a wavelength ranging from 403 to 407 nm, and I-line having awavelength ranging from 363 to 367 nm, illuminating the baked polyimidelayer, that is, G-line and H-line, G-line and I-line, H-line and I-line,or G-line, H-line and I-line illuminate the baked polyimide layer, thendeveloping the exposed polyimide layer to form a polyimide opening inthe exposed polyimide layer exposing the pad 8000, then curing orheating the developed polyimide layer at a peak temperature of between290 and 400° C. for a time of between 20 and 150 minutes in a nitrogenambient or in an oxygen-free ambient, the cured polyimide layer having athickness of between 3 and 25 μm, and then removing the residualpolymeric material or other contaminants from the upper surface of thepad 8000 exposed by the polyimide opening with an O₂ plasma or a plasmacontaining fluorine of below 200 PPM and oxygen, such that the polymerlayer 99 can be patterned with an opening 990 in the polymer layer 99exposing the pad 8000. Alternatively, the developed polyimide layer canbe cured or heated at a temperature between 150 and 290° C., andpreferably of between 260 and 280° C., for a time of between 20 and 150minutes in a nitrogen ambient or in an oxygen-free ambient.

The pad 8000 can be used to be connected to the external circuit via awirebonding process, a solder bonding process or atape-automated-bonding (TAB) process, wherein the external circuit maybe another semiconductor chip, a flexible substrate comprising a polymerlayer (such as polyimide) having a thickness of between 30 and 200 amand not comprising any polymer layer with glass fiber, a glasssubstrate, a ceramic substrate comprising a ceramic material asinsulating layers between circuit layers, a silicon substrate, anorganic substrate, a printed circuit board (PCB) or a ball grid array(BGA) substrate.

After the polymer layer 99 and the opening 990 are formed, asemiconductor wafer formed with the over-passivation scheme 8 can bediced into a plurality of individual semiconductor chips.

FIGS. 18A to 18I show another alternative of process steps to form anover-passivation scheme 8 with three metal layers 801, 802 and 803.Metal layers 801 and 803 are formed by a single-emboss process, whilethe metal layer 802 is formed by a double-emboss process.

Referring to FIG. 18A, a first single-embossing process is used to formthe first metal layer 801 as described in FIGS. 15D-15H. Next, a firstinter-metal polymer layer 98 is deposited and patterned with openings980 to expose the first metal layer 801, as shown in process step ofFIG. 15I. FIG. 18A is at the same process step as FIG. 15I when thefirst metal layer 801 and the first inter-metal dieletric polymer layer98 are formed by a single-emboss metal process, and the inter-metaldielectric polymer layer 98 is deposited and patterned with openings 980exposing the first metal layer 801. The design of the first metal layer801 and the first inter-metal polymer openings 980 in FIG. 18A isslightly different from that in FIG. 15I to accommodate an additionalmetal layer. The process steps in FIGS. 18B-18G show a double-embossingprocess to form a second metal layer 802 and via plugs 897. Thespecification of the polymer layer 95, the metal layer 801 and thepolymer layer 98 shown in FIGS. 18A-18I can be referred to as thespecification of the polymer layer 95, the metal layer 801 and thepolymer layer 98 illustrated in FIGS. 15C-15K, respectively. The processof forming the polymer layer 95 shown in FIG. 18A can be referred to asthe polymer layer 95 illustrated in FIGS. 15C-15K. The process offorming the metal layer 801 shown in FIG. 18A can be referred to as themetal layer 801 illustrated in FIGS. 15C-15K. The process of forming thepolymer layer 98 shown in FIG. 18A can be referred to as the polymerlayer 98 illustrated in FIGS. 15C-15K.

Referring to FIG. 18B, a second adhesion/barrier/seed layer 8021 isdeposited on the polymer layer 98 and on the first metal layer 801exposed by the openings 980. The specification of the secondadhesion/barrier/seed layer 8021 shown in FIGS. 18B-18I can be referredto as the specification of the second adhesion/barrier/seed layer 8021illustrated in FIGS. 15J-15K. The process of forming the secondadhesion/barrier/seed layer 8021 shown in FIG. 18B can be referred to asthe process of forming the second adhesion/barrier/seed layer 8021illustrated in FIGS. 15J-15K.

Referring to FIG. 18C, a photoresist layer 73, such as positive-typephotoresist layer, is deposited on the seed layer of the secondadhesion/barrier/seed layer 8021. Next, the photoresist layer 73 ispatterned with exposure and development processes to form openings 730in the photoresist layer 73 exposing the seed layer of the secondadhesion/barrier/seed layer 8021. A 1× stepper or 1× contact aligner canbe used to expose the photoresist layer 73 during the process ofexposure.

For example, the photoresist layer 73 can be formed by spin-on coating apositive-type photosensitive polymer layer on the seed layer of thesecond adhesion/barrier/seed layer 8021, then exposing thephotosensitive polymer layer using a 1× stepper or 1× contact alignerwith at least two of G-line having a wavelength ranging from 434 to 438nm, H-line having a wavelength ranging from 403 to 407 nm, and I-linehaving a wavelength ranging from 363 to 367 nm, illuminating thephotosensitive polymer layer, that is, G-line and H-line, G-line andI-line, H-line and I-line, or G-line, H-line and I-line illuminate thephotosensitive polymer layer, then developing the exposed polymer layer,and then removing the residual polymeric material or other contaminantsfrom the seed layer with an O₂ plasma or a plasma containing fluorine ofbelow 200 PPM and oxygen, such that the photoresist layer 73 can bepatterned with openings 730 in the photoresist layer 73 exposing theseed layer.

Next, a bulk conduction layer 8022 can be electroplated and/orelectroless plated over the seed layer exposed by the openings 730. Thebulk conduction layer 8022 may be a single layer of gold, copper,silver, palladium, platinum, rhodium, ruthenium, rhenium or nickel, or acomposite layer made of the above mentioned metals. The specification ofthe bulk conduction metal layer 8022 shown in FIGS. 18C-18I can bereferred to as the specification of the bulk conduction metal layer 8012illustrated in FIGS. 15F-15K. The process of forming the bulk conductionmetal layer 8022 shown in FIGS. 18C-18I can be referred to as theprocess of forming the bulk conduction metal layer 8012 illustrated inFIGS. 15F-15K.

Referring to FIG. 18D, the photoresist layer 73 is then stripped usingan organic solution with amide. However, some residuals from thephotoresist layer 73 could remain on the bulk conduction metal layer8022 and on the seed layer of the adhesion/barrier/seed layer 8021.Thereafter, the residuals can be removed from the seed layer of theadhesion/barrier/seed layer 8021 and from the bulk conduction metallayer 8022 with a plasma, such as O₂ plasma or plasma containingfluorine of below 200 PPM and oxygen.

Referring to FIG. 18E, a photoresist layer 74 is then deposied andpatterned to form openings 740 over the second bulk conduction metallayer 8022 and/or to optionally form openings 740′ directly on the seedlayer of the second adhesion/barrier/seed layer 8021. For example, thephotoresist layer 74 can be formed by spin-on coating a positive-typephotosensitive polymer layer on the seed layer of theadhesion/barrier/seed layer 8021 and on the bulk conduction metal layer8022, then exposing the photosensitive polymer layer using a 1× stepperor 1× contact aligner with at least two of G-line having a wavelengthranging from 434 to 438 nm , H-line having a wavelength ranging from 403to 407 nm, and I-line having a wavelength ranging from 363 to 367 nm,illuminating the photosensitive polymer layer, that is, G-line andH-line, G-line and I-line, H-line and I-line, or G-line, H-line andI-line illuminate the photosensitive polymer layer, then developing theexposed polymer layer, and then removing the residual polymeric materialor other contaminants from the seed layer and form the bulk conductionmetal layer 8022 with an O₂ plasma or a plasma containing fluorine ofbelow 200 PPM and oxygen, such that the photoresist layer 74 can bepatterned with the openings 740 and 740′ exposing the bulk conductionmetal layer 8022 and the seed layer of the adhesion/barrier/seed layer8021, respectively.

Next, a via plug layer is electroplated in the photoresist openings 740and 740′ to form via plugs 897 and metal piece 897′. The metal piece897′ can be used as described for the metal piece 898′ in FIG. 16D.

The material of the via plug 897 and metal piece 897′ may be gold orcopper. For example, the via plug 897 and metal piece 897′ may be formedby electroplating a gold layer with a thickness of between 1 and 100 μm,and preferably of between 2 and 30 μm, on the gold layer, exposed by theopenings 740, of the bulk conduction metal layer 8022, and on the seedlayer, made of gold, of the adhesion/barrier/seed layer 8021 exposed bythe openings 740′. Alternatively, the via plug 897 and metal piece 897′may be formed by electroplating a copper layer with a thickness ofbetween 1 and 100 μm, and preferably of between 2 and 30 μm, on thecopper layer, exposed by the openings 740, of the bulk conduction metallayer 8022, and on the seed layer, made of copper, of theadhesion/barrier/seed layer 8021 exposed by the openings 740′.

Referring to FIG. 18F, the photoresist layer 74 is then stripped usingan organic solution with amide. However, some residuals from thephotoresist layer 74 could remain on the exposed bulk conduction metallayer 8022, on the via plugs 897, on the metal piece 897′ and on theseed layer of the adhesion/barrier/seed layer 8021. Thereafter, theresiduals can be removed from the seed layer, from the via plugs 897,from the metal piece 897′ and from the bulk conduction metal layer 8022with a plasma, such as O₂ plasma or plasma containing fluorine of below200 PPM and oxygen.

Alternatively, after the bulk conduction metal layer 8022 is formed onthe seed layer of the adhesion/barrier/seed layer 8021 exposed by theopenings 730 illustrated in FIG. 18C, without removing the photoresistlayer 73, the photoresist layer 74 shown in FIG. 18E can be formed onthe photoresist layer 73 and on the bulk conduction metal layer 8022.The openings 740 in the photoresist layer 74 expose the bulk conductionmetal layer 8022, respectively, for defining the pattern of the viaplugs 897. The process for forming the via plugs 897 can be referred toas the above disclosure. Finally, the photoresist layers 73 and 74 areremoved using an organic solution with amide. However, some residualsfrom the photoresist layers 73 and 74 could remain on the bulkconduction metal layer 8022, on the via plugs 897 and on the seed layerof the adhesion/barrier/seed layer 8021. Thereafter, the residuals canbe removed from the seed layer of the adhesion/barrier/seed layer 8021,from the via plugs 897 and from the bulk conduction metal layer 8022with a plasma, such as O₂ plasma or plasma containing fluorine of below200 PPM and oxygen. Next, the adhesion/barrier/seed layer 8021 not underthe bulk conduction metal layer 8022 can be removed, as mentioned in theabove description.

Referring to FIG. 18C; the adhesion/barrier/seed layer 8021 not underthe bulk conduction metal layer 8022 and not under the metal piece 897′can be removed. The process of removing the adhesion/barrier/seed layer8021 not under the bulk conduction metal layer 8022 and not under thesecond metal piece 897′, as shown in FIG. 18G, can be referred to as theprocess of removing the adhesion/barrier/seed layer 8011 not under thebulk conduction metal layer 8012 and onto under the metal piece 898′, asillustrated in FIG. 16D.

Referring to FIG. 18H, a second inter-metal dielectric polymer layer 97is then deposited and planarized to expose the second via plugs 897. Thematerial of the polymer layer 97 may be polyimide (PI), benzocyclobutane(BCB), polyurethane, epoxy resin, a parylene-based polymer, asolder-mask material, an elastomer, silicone or a porous dielectricmaterial.

For example, the polymer layer 97 can be formed by spin-on coating anegative-type photosensitive polyimide layer, containing ester-typerprecursor, having a thickness of between 10 and 120 μm on the exposedbulk conduction metal layer 8022, on the via plugs 897, on the metalpiece 897′ and on the exposed polymer layer 98, then baking the spin-oncoated polyimide layer, then curing or heating the baked polyimide layerat a peak temperature of between 290 and 400° C. for a time of between20 and 150 minutes in a nitrogen ambient or in an oxygen-free ambient,the cured polyimide layer having a thickness of between 5 and 60 μm, andthen polishing or mechanical polishing, preferred chemical-mechanicalpolishing, an upper surface of the polymer layer 97 to uncover the viaplugs 897 and to planarize the upper surface thereof. Alternatively, thebaked polyimide layer can be cured or heated at a temperature between150 and 290° C., and preferably of between 260 and 280° C., for a timeof between 20 and 150 minutes in a nitrogen ambient or in an oxygen-freeambient.

FIG. 18I shows a completed structure by first forming the thirdmetallayer 803 is formed by a single-embossing process as described inFIGS. 17H-17I. Next, a cap polymer layer 99 is spin coated on thepatterned circuit layer 803, and an opening 990 is formed in the cappolymer layer 99 to expose a contact pad 8000 for interconnection to anexternal circuit. The specification of the adhesion/barrier/seed layer8031 and the bulk conduction metal layer 8032 shown in FIG. 18I can bereferred to as the specification of the adhesion/barrier/seed layer 8011and the bulk conduction metal layer 8012 illustrated in FIGS. 15D-15H,respectively. The process of forming the adhesion/barrier/seed layer8031 shown in FIG. 18I can be referred to as the process of forming theadhesion/barrier/seed layer 8011 illustrated in FIGS. 15D-15H. Theprocess of forming the bulk conduction metal layer 8032 shown in FIG.18I can be referred to as the process of forming the bulk conductionmetal layer 8012 illustrated in FIGS. 15D-15H. The specification of thepolymer layer 99 shown in FIG. 18I can be referred to as thespecification of the polymer layer 99 illustrated in FIG. 17J. Theprocess of forming the polymer layer 99 shown in FIG. 18I can bereferred to as the process of forming the polymer layer 99 and theopening 990 illustrated in FIG. 17J.

The pad 8000 can be used to be connected to the external circuit via awirebonding process, a solder bonding process or atape-automated-bonding (TAB) process, wherein the external circuit maybe another semiconductor chip, a flexible substrate comprising a polymerlayer (such as polyimide) having a thickness of between 30 and 200 μmand not comprising any polymer layer with glass fiber, a glasssubstrate, a ceramic substrate comprising a ceramic material asinsulating layers between circuit layers, a silicon substrate, anorganic substrate, a printed circuit board (PCB) or a ball grid array(BGA) substrate.

After the polymer layer 99 and the opening 990 are formed, asemiconductor wafer formed with the over-passivation scheme 8 can bediced into a plurality of individual semiconductor chips. FIGS. 19A to19. I show another alternative of process steps to form anover-passivation scheme 8 with two metal layers 801 and 802. The metallayer 801 is formed by a double-emboss process, while the metal layer802 is formed by a single-emboss process.

Referring to FIG. 19A, after the process steps of FIGS. 15C-15G and16A-16F for forming the polymer layer 95, the openings 950, the metallayer 801, the via plugs 898, the metal pieces 898′ and the polymerlayer 98 are completed, a polymer layer 97 can be formed on the polymerlayer 98, multiple openings 970 in the polymer layer 97 exposing the viaplugs 898. The material of the polymer layer 97 may be polyimide (PI),benzocyclobutane (BCB), polyurethane, epoxy resin, a parylene-basedpolymer, a solder-mask material, an elastomer, silicone or a porousdielectric material.

For example, the polymer layer 97 can be formed by spin-on coating anegative-type photosensitive polyimide layer, containing ester-typerprecursor, having a thickness of between 6 and 50 μm on the polymerlayer 98 and on the exposed via plugs 898, then baking the spin-oncoated polyimide layer, then exposing the baked polyimide layer using a1× stepper or 1× contact aligner with at least two of G-line having awavelength ranging from 434 to 438 nm, H-line having a wavelengthranging from 403 to 407 nm, and I-line having a wavelength ranging from363 to 367 nm, illuminating the baked polyimide layer, that is, G-lineand H-line, G-line and I-line, H-line and I-line, or G-line, H-line andI-line illuminate the baked polyimide layer, then developing the exposedpolyimide layer to form polyimide openings in the exposed polyimidelayer exposing the exposed via plugs 898, then curing or heating thedeveloped polyimide layer at a peak temperature of between 290 and 400°C. for a time of between 20 and 150 minutes in a nitrogen ambient or inan oxygen-free ambient, the cured polyimide layer having a thickness ofbetween 3 and 25 μm, and then removing the residual polymeric materialor other contaminants from the upper surface of the via plugs 898exposed by the polyimide openings with an O₂ plasma or a plasmacontaining fluorine of below 200 PPM and oxygen, such that the polymerlayer 97 can be patterned with openings 970 exposing the via plugs 898.Alternatively, the developed polyimide layer can be cured or heated at atemperature between 150 and 290° C., and preferably of between 260 and280° C., for a time of between 20 and 150 minutes in a nitrogen ambientor in an oxygen-free ambient. Referring to FIG. 19B, anadhesion/barrier/seed layer 8021 is deposited, preferred by sputtering,on the polymer layer 97 and on the via plugs 898 exposed by the openings970. Alternatively, the adhesion/barrier/seed layer 8021 can be formedby a process including a vapor deposition method, an evaporation method,a CVD method, an electroless plating method or a PVD method. Thespecification of the adhesion/barrier/seed layer 8021 shown in FIGS.19B-19I can be referred to as the specification of theadhesion/barrier/seed layer 8011 illustrated in FIGS. 15D-15K. Theprocess of forming the adhesion/barrier/seed layer 8021 shown in FIG.19B can be referred to as the process of forming theadhesion/barrier/seed layer 8011 illustrated in FIGS. 15D-15K.

Referring to FIG. 19C, a photoresist layer 73, such as positive-typephotoresist layer, is formed on the adhesion/barrier/seed layer 8021.Next, the photoresist layer 73 is patterned with exposure anddevelopment processes to form openings 730 in the photoresist layer 73exposing the adhesion/barrier/seed layer 8021. A 1× stepper or 1×contact aligner can be used to expose the photoresist layer 730 duringthe process of exposure. The process of forming the photoresist layer 73and the openings 730 in the photoresist layer 73 shown in FIG. 19C canbe referred to as the process of forming the photoresist layer 73 andthe openings 730 in the photoresist layer 73 illustrated in FIG. 18C.

Referring to FIG. 19D, a bulk conduction metal layer 8022 can beelectroplated and/or electroless plated over the adhesion/barrier/seedlayer 8021 exposed by the openings 730. The bulk conduction layer 8022may be a single layer of gold, copper, silver, palladium, platinum,rhodium, ruthenium, rhenium or nickel, or a composite layer made of theabove mentioned metals. The specification of the bulk conduction metallayer 8022 shown in FIGS. 19D-19I can be referred to as thespecification of the bulk conduction metal layer 8012 illustrated inFIGS. 15F-15K. The process of forming the bulk conduction metal layer8022 shown in FIGS. 19D can be referred to as the process of forming thebulk conduction metal layer 8012 illustrated in FIGS. 15F-15K.

Referring to FIG. 19E, after the bulk conduction metal layer 8022 isformed, most of the photoresist layer 73 can be removed using an organicsolution with amide. However, some residuals from the photoresist layer73 could remain on the bulk conduction metal layer 8022 and on the seedlayer of the adhesion/barrier/seed layer 8021. Thereafter, the residualscan be removed from the bulk conduction metal layer 8022 and from theseed layer with a plasma, such as O₂ plasma or plasma containingfluorine of below 200 PPM and oxygen.

Referring to FIG. 19F, the adhesion/barrier/seed layer 8021 not underthe bulk conduction metal layer 8022 is removed with a dry etchingmethod or a wet etching method. As to the wet etching method, when theseed layer of the adhesion/barrier/seed layer 8021 is a gold layer, itcan be etched with an iodine-containing solution, such as solutioncontaining potassium iodide; when the seed layer of theadhesion/barrier/seed layer 8021 is a copper layer, it can be etchedwith a solution containing NH₄OH; when the adhesion/barrier layer of theadhesion/barrier/seed layer 8021 is a titanium-tungsten-alloy layer, itcan be etched with a solution containing hydrogen peroxide; when theadhesion/barrier layer of the adhesion/barrier/seed layer 8021 is atitanium layer, it can be etched with a solution containing hydrogenfluoride; when the adhesion/barrier layer of the adhesion/barrier/seedlayer 8021 is a chromium layer, it can be etched with a solutioncontaining potassium ferricyanide. As to the dry etching method, whenthe seed layer of the adhesion/barrier/seed layer 8021 is a gold layer,it can be removed with an ion milling process or with an Ar sputteringetching process; when the adhesion/barrier layer of theadhesion/barrier/seed layer 8021 is a titanium layer or atitanium-tungsten-alloy layer, it can be etched with achlorine-containing plasma etching process or with an RIE process.Generally, the dry etching method to etch the adhesion/barrier/seedlayer 8021 not under the bulk conduction metal layer 8022 may include achemical plasma etching process, a sputtering etching process, such asargon sputter process, or a chemical vapor etching process.

Thereby, a second metal layer 802 can be formed on the polymer layer 97and on the via plugs 898 exposed by the openings 970, and the secondmetal layer 802 is formed with the adhesion/barrier/seed layer 8021 andthe bulk conduction metal layer 8022 on the adhesion/barrier/seed layer8021.

Referring to FIG. 19G, a polymer layer 99 is formed on the exposedpolymer layer 97 and on the bulk conduction metal layer 8022 via aspin-on coating process. Referring to FIG. 19H, the polymer layer 99 ispatterned with exposure and development processes to form an polymeropening 990 in the polymer layer 99 exposing the pad 8000.Alternatively, the polymer layer 99 may be formed by a laminationprocess or a screen-printing process. The material of the polymer layer99 may be polyimide (PI), benzocyclobutane (BCB), polyurethane, epoxyresin, a parylene-based polymer, a solder-mask material, an elastomer,silicone or a porous dielectric material.

For example, the polymer layer 99 can be formed by spin-on coating anegative-type photosensitive polyimide layer, containing ester-typerprecursor, having a thickness of between 6 and 50 μm on the exposedpolymer layer 97 and on the bulk conduction metal layer 8022, thenbaking the spin-on coated polyimide layer, then exposing the bakedpolyimide layer using a 1× stepper or 1× contact aligner with at leasttwo of G-line having a wavelength ranging from 434 to 438 nm, H-linehaving a wavelength ranging from 403 to 407 nm, and I-line having awavelength ranging from 363 to 367 nm, illuminating the baked polyimidelayer, that is, G-line and H-line, G-line and I-line, H-line and I-line,or G-line, H-line and I-line illuminate the baked polyimide layer, thendeveloping the exposed polyimide layer to form an polyimide opening inthe exposed polyimide layer exposing the pad 8000, then curing orheating the developed polyimide layer at a peak temperature of between290 and 400° C. for a time of between 20 and 150 minutes in a nitrogenambient or in an oxygen-free ambient, the cured polyimide layer having athickness of between 3 and 25 μm, and then removing the residualpolymeric material or other contaminants from the upper surface of thepad 8000 exposed by the polyimide opening with an O₂ plasma or a plasmacontaining fluorine of below 200 PPM and oxygen, such that the polymerlayer 99 can be patterned with an opening 990 in the polymer layer 99exposing the pad 8000. Alternatively, the developed polyimide layer canbe cured or heated at a temperature between 150 and 290° C., andpreferably of between 260 and 280° C., for a time of between 20 and 150minutes in a nitrogen ambient or in an oxygen-free ambient.

After the polymer layer 99 and the opening 990 are formed, asemiconductor wafer formed with the over-passivation scheme 8 can bediced into a plurality of individual semiconductor chips. The method ofconnecting the contact pad 8000 in FIG. 19I to an external circuit canbe referred to as the method of connecting the contact pad 8000 in FIG.15K to an external circuit. The external circuit may be anothersemiconductor chip, a flexible substrate comprising a polymer layer(such as polyimide) having a thickness of between 30 and 200 μm and notcomprising any polymer layer with glass fiber, a glass substrate, aceramic substrate comprising a ceramic material as insulating layersbetween circuit layers, a silicon substrate, an organic substrate, aprinted circuit board (PCB) or a ball grid array (BGA) substrate. Forexample, referring to FIG. 19I, via a wirebonding process, a wire 89′,such as gold wire, copper wire or aluminum wire, can be bonded to thepad 8000 of the individual semiconductor chip.

Alternatively, the contact structure 89 illustrated in FIG. 15L can beformed over the pad 8000 exposed by the opening 990. Under the contactstructure 89 may be an adhesion/barrier layer 891. After the wafer isformed with the contact structure 89, it can be diced into a pluralityof individual semiconductor chips.

FIGS. 21 and 22 show top views of a MOS transistor that can be a PMOStransistor or an NMOS transistor. Referring to FIG. 21, a transistorcomprises an active region 200, diffusion region, in or over the siliconsubstrate 1, a field oxide region 202 on the silicon substrate 1 andaround the active region 200, a gate 204 on the field oxide region 202and across the active region 200, and a gate oxide (not shown) betweenthe active region 200 and the gate 204. The active region 200 can bedefined as a source 206 at a side of the gate 204, and a drain 208 atthe other side of the gate 204. The material of the gate 204 may be polysilicon, metal silicide or composite layer of above materials, whereinthe metal silicide may be NiSi, CoS, TiSi₂ or WSi. Alternatively, thematerial of the gate 204 may be a metal, such as W, WN, TiN, Ta, TaN,Mo, or alloy or composite layer of above materials. The material of thegate oxide may be silicon oxide or high k oxide, such as Hf containingoxide. The Hf containing oxide may be HfO₂, HfSiON or HfSiO. Theabove-mentioned physical channel width and physical channel length inall embodiments can be defined in FIG. 21. The reference mark of W isdefined as the physical channel width of the transistor, the length ofthe gate 204 crossing over the diffusion region 200; the reference markof L is defined as the physical channel length of the transistor, thewidth of the gate 204 over the diffusion region 200.

Referring to FIG. 22, alternatively, a transistor may include a gate 204with multiple portions 204 ₁-204 _(n) over one or more diffusion regions200. The reference marks of W₁-W_(n) are defined as the physical channelwidth of each portion 204 ₁-204 _(n) of the gate 204, the length of eachportion 204 ₁-204 _(n) of the gate 204 crossing over the diffusionregion 200; the reference mark of L is defined as the physical channellength of one of the portions 204 ₁-204 _(n) of the gate 204, the widthof one of the portions 204 ₁-204 _(n) of the gate 204 over the diffusionregion 200. In this case, the physical channel width W of the transistoris the summation of the physical channel widths W₁-W_(n) of eachportions 204 ₁-204 _(n) of the gate 204, and the physical channel lengthL of the transistor is the physical channel length L of one of theportions 204 ₁-204 _(n) of the gate 204.

Those described above are the embodiments to exemplify the presentinvention to enable the person skilled in the art to understand, makeand use the present invention. However, it is not intended to limit thescope of the present invention. Any equivalent modification andvariation according to the spirit of the present invention is to be alsoincluded within the scope of the claims stated below.

What is claimed is:
 1. An integrated circuit chip comprising: a siliconsubstrate; a voltage converter in or over said silicon substrate,wherein said voltage converter has a first node at a first voltage levelof Vcc output from said voltage converter and a second node at a secondvoltage level of Vdd supplied from an external circuit, wherein saidfirst voltage level is different from said second voltage level; aninternal circuit in or over said silicon substrate, wherein saidinternal circuit comprises an NMOS transistor, wherein a ratio of aphysical channel width of said NMOS transistor to a physical channellength of said NMOS transistor ranges from 0.1 to 20; a dielectricstructure over said silicon substrate; a first interconnecting structureover said silicon substrate and in or over said dielectric structure,wherein said first interconnecting structure is connected to said firstnode of said voltage converter; a first pad over said silicon substrate,wherein said first pad is connected to said first interconnectingstructure; a second interconnecting structure over said siliconsubstrate and in or over said dielectric structure, wherein said secondinterconnecting structure is connected to a first node of said internalcircuit; a second pad over said silicon substrate, wherein said secondpad is connected to said second interconnecting structure; a passivationlayer over said dielectric structure, wherein said passivation layercomprises an oxide layer and a nitride layer over said oxide layer, andwherein a first opening in said passivation layer exposes said firstpad, and a second opening in said passivation layer exposes said secondpad, wherein said second opening has a width between 0.1 and 30micrometers; and a third interconnecting structure over said passivationlayer and over said first and second pads, wherein said first node ofsaid voltage converter is connected to said first node of said internalcircuit through, in sequence, said first interconnecting structure, saidfirst pad, said third interconnecting structure, said second pad andsaid second interconnecting structure, and wherein said thirdinterconnecting structure comprises an adhesion/barrier layer, a seedlayer on said adhesion/barrier layer, and an electroplated metal layeron said seed layer, wherein said electroplated metal layer has athickness between 2 and 30 micrometers.
 2. The integrated circuit chipof claim 1 further comprising a fourth interconnecting structure oversaid silicon substrate and in or over said dielectric structure, whereinsaid fourth interconnecting structure is connected to a third node ofsaid voltage converter at a third voltage level of Vss, a third pad oversaid silicon substrate, wherein said third pad is connected to saidfourth interconnecting structure and is exposed by a third opening insaid passivation layer, a fifth interconnecting structure over saidsilicon substrate and in or over said dielectric structure, wherein saidfifth interconnecting structure is connected to a second node of saidinternal circuit, a fourth pad over said silicon substrate, wherein saidfourth pad is connected to said fifth interconnecting structure and isexposed by a fourth opening in said passivation layer, and a sixthinterconnecting structure over said passivation layer and over saidthird and fourth pads, wherein said third node of said voltage converteris connected to said second node of said internal circuit through, insequence, said fourth interconnecting structure, said third pad, saidsixth interconnecting structure, said fourth pad and said fifthinterconnecting structure.
 3. The integrated circuit chip of claim 1,wherein said first voltage level of Vcc is between 0.6 and 3 volts, andsaid second voltage level of Vdd is between 3 and 5 volts.
 4. Theintegrated circuit chip of claim 1, wherein said nitride layer has athickness between 0.2 and 1.5 micrometers.
 5. The integrated circuitchip of claim 1, wherein said first voltage level of Vcc is between 0.6and 2 volts, and said second voltage level of Vdd is between 2 and 3volts.
 6. The integrated circuit chip of claim 1 further comprising apolymer layer between said third interconnecting structure and saidpassivation layer.
 7. The integrated circuit chip of claim 6, whereinsaid polymer layer has a thickness between 2 and 30 micrometers.
 8. Theintegrated circuit chip of claim 1, wherein said electroplated metallayer comprises a copper layer having a thickness between 2 and 30micrometers.
 9. An integrated circuit chip comprising: a siliconsubstrate; a voltage converter in or over said silicon substrate,wherein said voltage converter has a first node at a first voltage levelof Vcc output from said voltage converter and a second node at a secondvoltage level of Vdd supplied from an external circuit, wherein saidfirst voltage level is different from said second voltage level; aninternal circuit in or over said silicon substrate, wherein saidinternal circuit comprises an NMOS transistor, wherein a ratio of aphysical channel width of said NMOS transistor to a physical channellength of said NMOS transistor ranges from 0.1 to 20; a dielectricstructure over said silicon substrate; a first interconnecting structureover said silicon substrate and in or over said dielectric structure,wherein said first interconnecting structure is connected to said firstnode of said voltage converter; a first pad over said silicon substrate,wherein said first pad is connected to said first interconnectingstructure; a second interconnecting structure over said siliconsubstrate and in or over said dielectric structure, wherein said secondinterconnecting structure is connected to a first node of said internalcircuit; a second pad over said silicon substrate, wherein said secondpad is connected to said second interconnecting structure; a passivationlayer over said dielectric structure; a polymer layer over saidpassivation layer, wherein said polymer layer has a thickness between 2and 30 micrometers, and wherein a first opening in said polymer layerexposes said first pad, and a second opening in said polymer layerexposes said second pad; and a third interconnecting structure over saidpolymer layer and over said first and second pads, wherein said firstnode of said voltage converter is connected to said first node of saidinternal circuit through, in sequence, said first interconnectingstructure, said first pad, said third interconnecting structure, saidsecond pad and said second interconnecting structure, and wherein saidthird interconnecting structure comprises an adhesion/barrier layer, aseed layer on said adhesion/barrier layer, and an electroplated metallayer on said seed layer, wherein said electroplated metal layer has athickness between 2 and 30 micrometers.
 10. The integrated circuit chipof claim 9 further comprising a fourth interconnecting structure oversaid silicon substrate and in or over said dielectric structure, whereinsaid fourth interconnecting structure is connected to a third node ofsaid voltage converter at a third voltage of Vss, a third pad over saidsilicon substrate, wherein said third pad is connected to said fourthinterconnecting structure and is exposed by a third opening in saidpolymer layer, a fifth interconnecting structure over said siliconsubstrate and in or over said dielectric structure, wherein said fifthinterconnecting structure is connected to a second node of said internalcircuit, a fourth pad over said silicon substrate, wherein said fourthpad is connected to said fifth interconnecting structure and is exposedby a fourth opening in said polymer layer, and a sixth interconnectingstructure over said polymer layer and over said third and fourth pads,wherein said third node of said voltage converter is connected to saidsecond node of said internal circuit through, in sequence, said fourthinterconnecting structure, said third pad, said sixth interconnectingstructure, said fourth pad and said fifth interconnecting structure. 11.The integrated circuit chip of claim 9, wherein said first voltage levelof Vcc is between 0.6 and 3 volts, and said second voltage level of Vddis between 3 and 5 volts.
 12. The integrated circuit chip of claim 9,wherein said passivation layer comprises a nitride layer having athickness between 0.2 and 1.5 micrometers.
 13. The integrated circuitchip of claim 9, wherein said electroplated metal layer comprises acopper layer having a thickness between 2 and 30 micrometers.
 14. Anintegrated circuit chip comprising: a semiconductor substrate; a voltageconverter in or over said semiconductor substrate; an internal circuitin or over said semiconductor substrate, wherein said internal circuitcomprises an NMOS transistor, wherein a ratio of a physical channelwidth of said NMOS transistor to a physical channel length of said NMOStransistor ranges from 0.1 to 20; an ESD circuit in or over saidsemiconductor substrate; a dielectric structure over said semiconductorsubstrate; a first interconnecting structure over said semiconductorsubstrate and in or over said dielectric structure, wherein said firstinterconnecting structure is connected to a first node of said ESDcircuit; a first pad over said semiconductor substrate, wherein saidfirst pad is connected to said first node of said ESD circuit throughsaid first interconnecting structure; a second interconnecting structureover said semiconductor substrate and in or over said dielectricstructure, wherein said second interconnecting structure is connected toa first node of said voltage converter; a second pad over saidsemiconductor substrate, wherein said second pad is connected to saidfirst node of said voltage converter through said second interconnectingstructure; a third interconnecting structure over said semiconductorsubstrate and in or over said dielectric structure, wherein said thirdinterconnecting structure is connected to a second node of said voltageconverter; a third pad over said semiconductor substrate, wherein saidthird pad is connected to said second node of said voltage converterthrough said third interconnecting structure; a fourth interconnectingstructure over said semiconductor substrate and in or over saiddielectric structure, wherein said fourth interconnecting structure isconnected to a first node of said internal circuit; a fourth pad oversaid semiconductor substrate, wherein said fourth pad is connected tosaid first node of said internal circuit through said fourthinterconnecting structure; a passivation layer over said dielectricstructure, wherein a first opening in said passivation layer exposessaid first pad, a second opening in said passivation layer exposes saidsecond pad, a third opening in said passivation layer exposes said thirdpad, and a fourth opening in said passivation layer exposes said fourthpad; a fifth interconnecting structure over said passivation layer andover said first and second pads, wherein said first node of said ESDcircuit is connected to said first node of said voltage converterthrough, in sequence, said first interconnecting structure, said firstpad, said fifth interconnecting structure, said second pad and saidsecond interconnecting structure; and a sixth interconnecting structureover said passivation layer and over said third and fourth pads, whereinsaid second node of said voltage converter is connected to said firstnode of said internal circuit through, in sequence, said thirdinterconnecting structure, said third pad, said sixth interconnectingstructure, said fourth pad and said fourth interconnecting structure,and wherein said sixth interconnecting structure comprises anadhesion/barrier layer, a seed layer on said adhesion/barrier layer, andan electroplated metal layer on said seed layer, wherein saidelectroplated metal layer has a thickness between 2 and 30 micrometers.15. The integrated circuit chip of claim 14 further comprising a seventhinterconnecting structure over said semiconductor substrate and in orover said dielectric structure, wherein said seventh interconnectingstructure is connected to a second node of said ESD circuit, a fifth padover said semiconductor substrate, wherein said fifth pad is connectedto said second node of said ESD circuit through said seventhinterconnecting structure and is exposed by a fifth opening in saidpassivation layer, an eighth interconnecting structure over saidsemiconductor substrate and in or over said dielectric structure,wherein said eighth interconnecting structure is connected to a thirdnode of said voltage converter, a sixth pad over said semiconductorsubstrate, wherein said sixth pad is connected to said third node ofsaid voltage converter through said eighth interconnecting structure andis exposed by a sixth opening in said passivation layer, a ninthinterconnecting structure over said semiconductor substrate and in orover said dielectric structure, wherein said ninth interconnectingstructure is connected to a second node of said internal circuit, aseventh pad over said semiconductor substrate, wherein said seventh padis connected to said second node of said internal circuit through saidninth interconnecting structure and is exposed by a seventh opening insaid passivation layer, and a tenth interconnecting structure over saidpassivation layer and over said fifth, sixth and seventh pads, whereinsaid third node of said voltage converter is connected to said secondnode of said ESD circuit through, in sequence, said eighthinterconnecting structure, said sixth pad, said tenth interconnectingstructure, said fifth pad and said seventh interconnecting structure,and wherein said third node of said voltage converter is connected tosaid second node of said internal circuit through, in sequence, saideighth interconnecting structure, said sixth pad, said tenthinterconnecting structure, said seventh pad and said ninthinterconnecting structure.
 16. The integrated circuit chip of claim 14,wherein said sixth interconnecting structure is at a first voltage levelof Vcc between 0.6 and 3 volts, and said fifth interconnecting structureis at a second voltage level of Vdd between 3 and 5 volts.
 17. Theintegrated circuit chip of claim 14, wherein said passivation layercomprises a nitride layer having a thickness between 0.2 and 1.5micrometers.
 18. The integrated circuit chip of claim 14, wherein saidfourth opening has a width between 0.1 and 30 micrometers.
 19. Theintegrated circuit chip of claim 14 further comprising a polymer layerbetween said fifth interconnecting structure and said passivation layerand between said sixth interconnecting structure and said passivationlayer.
 20. The integrated circuit chip of claim 14, wherein saidelectroplated metal layer comprises a copper layer having a thicknessbetween 2 and 30 micrometers.